Xylitol synthesis method

FIELD: chemistry.

SUBSTANCE: present invention relates to versions of a xylitol synthesis method which is widely used in production of confectionaries, as well as in products for preventing diseases of the oral cavity, health improving products, pharmaceutical products etc. One version of the method involves electrochemical oxidative decarboxylation of an uronic acid compound involving a furanose or pyranose cycle to obtain a xylitol synthesis intermediate product and hydrogenation of the xylitol synthesis intermediate product to obtain xylitol. One more version of the method involves hydrolysis of a D-glucuronic acid compound, decarboxylation of the D-glucuronic acid compound to obtain a dialdehyde xylitol synthesis intermediate product and hydrogenation of the xylitol synthesis intermediate product in the presence of a hydrogenation catalyst to obtain xylitol.

EFFECT: invention provides a cheap xylitol synthesis method with high output at minimal losses.

20 cl, 6 dwg, 5 ex

 

This application claims the benefit of continued application US No. 60/556571, "the Methods of production of xylitol", registered on March 26, 2004, which is incorporated here by reference in its entirety.

The technical field to which the invention relates.

The present invention relates to methods for production of xylitol. In particular, the invention provides methods of producing xylitol comprising the oxidative decarboxylation of compounds.

The level of technology

Xylitol is a naturally occurring five-carbon sweet alcohol, present in many fruits and vegetables and produced in the human body during normal metabolism. Xylitol is also an important industrial product and is widely used in the manufacture of confectionery, including messagenow chewing gum, breath mints and dry hard candy, as well as in products for the prevention of diseases of the oral cavity, products to improve health, pharmaceutical products, etc.

Certain properties of xylitol make it attractive sweetener or sugar substitute in various cases, especially in the production of sweetened food products. For example, xylitol is non-toxic and has about the same sweetness as sucrose, at a lower energy value, the composition of the managing of about 2.4 kcal/g Xylitol is metabolized independently of glucose and can be used without the risk of persons with non-insulin diabetes, has a low glycemic index and, as shown, has antiketogenic effect in diabetes. The xylitol crystals are dissolved with heat absorption and create a feeling of coolness when dissolved in the mouth. It is believed that xylitol is cariostatic and even anticariogenic, and it is believed that it is not used by the microflora of the mouth, producing plaques. Indeed, the use xylitol instead of sugar is associated with the reduction of dental caries. In General, xylitol is the preferred sweetener.

Xylitol usually get ways using different natural raw materials, especially materials containing xylan. Xylitol can be obtained in a variety of ways, including the hydrogenation of xylose derived from hydrolyzed hemicellulose (xylan or arabinoxylan), as disclosed in US patents No. 2989569, 3558725 and 4008285.

Catalytic hydrogenation of D-xylose in hemicellulose hydrolysates remains the primary industrial source of xylitol. Industrial production of D-xylose primarily through hydrolysis of hemicelluloses (Xylenol and arabinoxylans). However, many of these methods of producing xylitol expensive and require a lot of time, and was offered a number of alternative the ways of synthesis of xylitol. Such methods include various synthetic chemical processes, the use of microorganisms and methods such as fermentation. However, despite these results, there is a need to produce xylitol in a way that is characterized by low cost and yield of the purified product. Reducing the number of trash (losses) in its production is also desirable. Due to the increased use of xylitol, in particular due to its properties as a sweetener and therapeutic effects, there is a continuing need in the way of production of xylitol.

Disclosure of inventions

The provided methods of producing xylitol comprising the oxidative decarboxylation of the substrate reagent. Preferably, the oxidative decarboxylation to produce one of two ways. In the first implementation of the oxidative decarboxylation to produce electrochemical method, preferably, such as anodic oxidative decarboxylation of the substrate reagent. In the second implementation of the oxidative decarboxylation of the substrate reagent is conducted through one or more chemical reactions.

A large variety of reagents, substrates can be used to implement the methods of production of xylitol. The reagent substrate can be the source material for the reaction acyclical the th decarboxylation or can be obtained from any suitable material predecessor. Preferred materials predecessor are uronic acids, including the structure furanose or pyranose cycle. In some aspects of the implementation of one or more material precursor may undergo one or more chemical reactions, such as oxidation reaction, reduction reaction of or hydrolysis to obtain a suitable substrate reagent.

Figure 1 shows the basic reaction scheme 10' for the production of xylitol according to some implementations. Reaction scheme 10' includes the steps of providing the substrate reagent 50', includes link uronic acid, and oxidative decarboxylation reagent substrate 55'. Suitable reagents substrates include containing uronic acid reagents substrates that undergo the desired reaction decarboxylation under certain reaction conditions. In one implementation of the method of producing xylitol includes the steps of providing the substrate reagent 50', which includes the balance of uronic acid and oxidative decarboxylation 55' reagent substrate by electrochemical oxidative decarboxylation of a suitable substrate reagent. Preferably the reagent substrate includes a link uronic acid with the structure of pyranose or furanose cycle. In an alternative implementation methods for the obtaining xylitol includes the steps of providing the substrate reagent 50', including balance of uronic acid, and oxidative decarboxylation 55' reagent substrate by chemical oxidative decarboxylation of a suitable substrate reagent. Preferably the reagent is a substrate of the second implementation includes link L-gulonovoy acid.

On the stage 55' oxidative decarboxylation obtained intermediate of the synthesis of xylitol connection 60' or alternative turns out to xylitol or other connection, applicable for obtaining xylitol. You can produce various intermediates for the synthesis of xylitol, and intermediates for the synthesis of xylitol received on the first exercise, may be the same or different from the intermediates of the synthesis of xylitol produced by the methods of the second implementation. Reagent substrate can be 50', provided as the source material, or it may be obtained from one or more materials predecessor.

Figure 1 is a method of producing xylitol 10' further includes the steps of: providing source material 20', chemical modification 25' source material 20' for receiving the first material precursor 30', chemical modification 35' of the first of the preceding material 30' for receiving the second material precursor 40' and chemical modification 45' of the second material precursor 40' for receiving the reagent substrate is 50'. Intermediate of the synthesis of xylitol 60' chemically modify 65' for the production of the reaction product, including xylitol 70'. Preferably the reaction product includes xylitol with the release of not less than 20% of theoretical yield of xylitol. Chemical modification of the source material, the material of the precursor or intermediate of the synthesis of xylitol may designate any appropriate reaction or series of reactions, which modifies the chemical structure of the material, including oxidation reaction, reduction reaction of, hydrolysis or condensation reaction.

In one preferred aspect of the first implementation method for the production of xylitol includes the step of electrochemical oxidative decarboxylation of the substrate reagent D-glucuronic acid reagent substrate D-fructofuranosidase acid or reagent substrate L-gulonovoy acid to produce an intermediate of the synthesis of xylitol. Preferably, the method includes the step of oxidative decarboxylation reagent substrate by anodic decarboxylation, where the reagent is a substrate selected from the group consisting of glycoside, oligosaccharide, polysaccharide, 1-phosphate or glycosyl-fluoride salt of D-glucuronic acid. On stage oxidative decarboxylation is intermediate of the synthesis of xylitol. Intermediate of the synthesis of xylitol is, prefer the Ino, dialdehydes or dicarbonyl structure, which, preferably, then restore using the hydrogenation catalyst and hydrogen gas with the release of the product, including xylitol.

In one preferred aspect of the second implementation of the method for the production of xylitol includes the step of oxidative decarboxylation of the substrate reagent D-glucuronic acid to produce dialdehyde intermediate for the synthesis of xylitol, such as D-Xylo-Penta-1,5-diose. Stage oxidative decarboxylation produces the first intermediate of the synthesis of xylitol, preferably, dialdehyde or dicarbonyl structure. In another preferred aspect of the second implementation of the method for the production of xylitol includes the step of oxidative decarboxylation of the substrate reagent L-gulonovoy acid to obtain an intermediate of the synthesis of xylitol, such as L-xylose, to obtain a second intermediate of the synthesis of xylitol, preferably, dialdehydes or dicarboxylic patterns. Preferably, in all aspects of the second implementation of the intermediates of the synthesis of xylitol further chemically modified, for example by reaction recovery/dehydrogenation, to obtain a reaction product comprising xylitol.

Brief description of drawings

The figure 1 shows the basic reaction synthesis process is Silit.

The figure 2 shows two reaction process for the synthesis of xylitol, including electrochemical oxidative decarboxylation.

The figure 3 shows the reaction scheme for method figure 2.

Figure 4 shows two reaction process for the synthesis of xylitol, including the processes of chemical oxidative decarboxylation.

The figure 5 shows the reaction scheme for the first method figure 4.

The figure 6 shows the reaction scheme for the second method, figure 4.

The implementation of the invention

The terms "about, approximately" or "substantially"also applies to the number, refer to the variations of these quantities that are equal to the above number, for example, the number of which differs slightly from the above number for that purpose or function for which it is intended. The variation in the number or relationship modified by the terms "about" or "substantially"include variations on the basis of the guidelines contained in the above and read by an ordinary specialist in the field of technology.

References to "compound D-factoranalysis (acid)" and "compound D-glucuronidase (acid)", as used here, includes glycosides, polymers or oligomers, and derivatives and salts of the above, unless otherwise specified.

The reference to "the compound D-Lukanova acid" as used here, includes glycosides, polymers or oligomers are preferably protected recovery group at the end and derivatives and salts of the above.

The reference to "a compound glucopyranose", as used here, includes glycosides, polymers or oligomers of α(alpha)-, β(beta)- and α,β(alpha, beta)-glucopyranose and derivatives and salts of the above.

The reference to "a compound fructofuranose", as used here, includes glycosides, polymers or oligomers of α(alpha)-, β(beta)- and α,β(alpha, beta)-fructofuranose and derivatives and salts of the above.

The reference to "connection glucopyranoside acid", as used here, includes glycosides, polymers or oligomers of α(alpha)-, β(beta)- and α,β(alpha, beta)-glucopyranoside acid and derivatives and salts of the above.

The term "source material" refers to a chemical substance that source is provided in the method of producing xylitol, to the reaction of oxidative decarboxylation. The source material can be chemically modified to produce material predecessor or it may be a reagent substrate the reaction of oxidative decarboxylation.

The term "material predecessor" refers to the product of the chemical modification of the source material or the product of the chemical modification of other material precursors is of Annika.

The term "reagent substrate" refers to a chemical substance that undergoes oxidative decarboxylation to obtain the intermediate of the synthesis of xylitol or product of the synthesis of xylitol. In some aspects, the source material is also a reagent substrate. The reagent substrate uronic acid is a reagent substrate, which includes at least one uronic acid residue.

The term "connection uronic acid", as used here, refers to the connection, including uronic acid, including certain glycosides, polymers or oligomers, and their respective salts. Connection uronic acid or derivatives and salts of the above preferably is able to transform into dialdehyde intermediates for the synthesis of xylitol or their derivatives and salts.

Synthesis of xylitol, including electrochemical oxidative decarboxylation

In the first implementation, schematically presented in figure 2, the methods for producing xylitol include stage oxidative decarboxylation carried out by electrochemical method, preferably by oxidative decarboxylation of the substrate reagent. The application of electrochemical decarboxylation in the synthesis of xylitol has many advantages. In particular, the process involved a little chemical regentova reaction can be very selective, so often it is easier to clean the product. Moreover, usually very little waste negligible the amount of by-products and usually a minimum consumption of reagents in the process of electrochemical decarboxylation.

Connection glucopyranose (1) is used as the source material for both processes are shown in figure 2, although any source material that can be transformed into a suitable reagent, a substrate can be used as a starting material or material predecessor. Connection glucopyranose (1) can oxidize (a) before the connection glucopyranoside acid (2A) in any suitable way with the oxidation reaction for the formation of the preferred substrate reagent. The original material or material precursor may include any D-glukuronidirovaniu group without replacement of oxygen in the 6th position, or D-fracturesfeeling group without replacement of oxygen in the loop. Reagent substrate (2A) is preferably a salt of D-glucuronic acid or its glycoside, oligomer or polymer or natural material, or obtained in the oxidation of (a). The reagent substrate (2A) optionally you can provide in the form of sodium, potassium, ammonium, calcium and/or magnesium salt.

The oxidation reaction (a) material precursor (1) to the reagent subs the rata can be carried out by methods known in the art, including, but not limited to, air oxidation/About2this catalyst as platinum, stable nitroxyl radicals (e.g., TEMPO with regeneration), oxidation of ions of transition metals with electrochemical regeneration and electrochemically. Suitable oxidation reaction (a) for the purpose of oxidation of compounds D-glucopyranosyl to compounds D-glucuronidase described in the following literature sources, which are incorporated here by reference in its entirety: K.Heyns et al, "Selective catalytic oxidation of carbohydrates, employing platinum catalysts," Advances in Carbohydrate Chemistry and Biochemistry, 17, 169-221 (1962); .Yamada et al., Air oxidation of cyclodextrin with a platinum catalyst," Journal of Applied Glycoscience, 47, 21-26 (2006); P.L.Bragd et al., "Selective oxidation of carbohydrates by 4-AcNH-TEMPO/peracid systems," Carbohydrate Polymers, 49, 397-406 (2002); K.Yasuda et al., "The simultaneous use of immobilized reagents for the one-pot conversion of alcohols to carboxylic acids," Journal of the Chemical Society, Perkin Transactions, 1, 1024-1025 (2002).

D-glucopyranoside acid (2A) can be used as a reagent, a substrate that undergoes electrochemical decarboxylation (C) with the formation of the intermediate of synthesis of xylitol (3). Otherwise glucopyranoside acid (2A) can be used as the material of the precursor, which undergoes hydrolysis (b) with the formation of substrate reagent D-glucuronic acid (2B). Hydrolysis of (b) connection D-glucopyranoside the OIC acid can be performed, using α and/or β-glucuronidase (or a mixture of both) or acid when heated to release the D-glucuronic acid. Glucuronic acid can be separated from any non-ionic saccharide using ion-exchange chromatography or electrodialysis. In any reaction method carboxyl portion of the substrate reagent (for example, the connection glucopyranoside acid (2A) or the reagent substrate D-glucuronic acid (2B) undergoes electrochemical decarboxylation (C) with the formation of the intermediate of synthesis of xylitol (3). Intermediate of the synthesis of xylitol obtained by both methods are shown in figure 2, includes D-Xylo-Penta-1,5-diosa (g). Preferably intermediate of the synthesis of xylitol (3) is dialdehydes as intermediates for the synthesis of xylitol.

Suitable reagents substrates for the stage electrochemical oxidative decarboxylation (in) substrate reagent preferably contain uronic acid, which preferably is in the form of a pyranose or furanose a cyclic structure. The reagent substrate may be a hydrocarbon (organic, carboxylic acid, such as aldonova or some saccharine acid, although the reagents, substrates, comprising uronic acid, are preferred. More specifically, the reagent substrate preferably includes a chemical part, selected from the group consisting the of the glycoside, oligosaccharide, polysaccharide, 1-phosphate or glycosyl-fluoride salt of D-glucuronic acid and D-factoranalysis (acid). Examples of preferred reagents of the substrates shown in figure 2 as the connection glucopyranoside acid (2A) or compound D-glucuronic acid (2B).

Stage oxidative decarboxylation of the substrate reagent (C) is preferably carried out using an electrochemical oxidative decarboxylation of the substrate reagent. The reactant substrate is preferably in its ionized form (e.g., salt) or in the form of the free compounds, or linked through glycosidic linkage with alcohol or other molecule. The appropriate reaction of oxidative decarboxylation () to obtain the intermediate of the synthesis of xylitol (3) is the reaction of oxidative decarboxylation, such as reaction Hofer-Space (Hofer, Moest, Annalen, 1902, 828, 284). The reaction Hofer-Space is described, for example, Kruis, Schanzer, Z. physikal. Chem., 1942, 191, A, 301, Neuberg (Biochemische Zeitschrift 7 (1908) 537). Decarboxylation of D-gluconic acid to D-arabinose was investigated as an economically important reaction, and have developed a flow-through reactor with a constant flow. The following literature sources included here by reference in its entirety: Pergola et al., Electrochimica Acta 39 (1994) 1415; Pezzatini et al., Electroanalysis 4 (1992) 129; Vallieres and Matlosz, J. Electrochem. Society 146 (199) 2933.

Device (install) for decarboxylation of the substrate reagent preferably includes an electrochemical cell. The anodic reaction of oxidative decarboxylation (C) can be performed using an electrochemical cell. The anode of the electrochemical cell can be made of any suitable material, but preferably of spectral pure graphite, pyrolytic carbon, graphite, wax impregnated, glassy carbon, dispersed graphite, dispersed carbon material, carbon fiber, coke or platinum in the form of a Packed base (bed), liquefied basis or porous anode. The US patent No. 950366, incorporated by reference in its entirety, discloses an installation for the decarboxylation of D-gluconic acid from D-arabinose, which can be used for the reaction of oxidative decarboxylation (in). The electrochemical cell preferably includes the anode of the electrochemical cell, where it is believed the reaction of oxidative decarboxylation (in). The surface area of the anode is preferably large, and may be made of many carbon materials, platinum or other metals. The contact between the source material and the anode causes decarboxylation, which leads to the liberation of carbon dioxide and the formation of interest is mediate synthesis of xylitol (3). Preferably, the electrochemical cell further includes a cathode, so that the inside of the electrochemical cell can undergo reaction.

It is believed that electrochemical oxidative decarboxylation occurs when the solution comprising the reagent substrate in contact with the anode of the electrochemical cell to which the applied potential. Without going into theory, we can say that the oxidative decarboxylation of compounds glucopyranoside acid leads to the formation of carbocation (ion Carbonia) at carbon 5, which is stabilized in the form of ion carbarsone (including the oxygen atom of the cycle). Adding a hydroxyl ion or water molecule to such an intermediate can form Polyacetal, which in the aquatic environment is disclosed, forming aldehyde (5 carbon) and Polyacetal at carbon 1. The latter decays to the aldehyde, forming a dialdehyde.

Other examples of ways electrochemical oxidation are described in the following sources, which are incorporated here by reference in its entirety: Schuurman et al., Studies in Surface Science and Catalysis, 72 (1992) 43; Applied Catalysis A: General 89 (1992) 31, 47, and references therein; P.L.Bragd, A.C.Besemer, H. van Bekkum, Carbohydrate Polymers 49 (2002) 397-406); Matsuoka et al., Fuel Cells 2 (2002) 35.

The implementation of electrochemical decarboxylation (in) substrate reagent, such as glucopyranoside acid (2A) or D-glucuronic to the slot (2B), gives the intermediate of synthesis of xylitol (3), such as D-Xylo-Penta-1,5-diaza (g). One or more subsequent chemical modification intermediate for the synthesis of xylitol (3), such as the reduction-hydrogenation of (e), leads to a mixture of products including xylitol (4). Non-ionic intermediate for the synthesis of xylitol (3) can be separated from unreacted starting material (2), for example, by anion-exchange chromatography or electrodialysis. The recovery of the intermediate synthesis of xylitol (3) can be performed in any suitable way known in the prior art, including, but not limited to catalytic hydrogenation. Effective catalysts include ruthenium and Nickel. In particular, we can apply the ruthenium catalyst on the carrier and Nickel of Renee. In one aspect, the intermediate of the synthesis of xylitol (3) it is possible to recover the hydrogen ruthenium (patent application WO No. 2004052813, fully included here by reference), Nickel (US patent No. 4008285, fully included here by reference), or other known hydrogenation catalyst to obtain xylitol (4). The hydrogenation is usually carried out at temperatures between about 70°and about 150°C and pressure of H2between approximately 0.1 and approximately 10 MPa. In contrast, it is possible to apply electrochemical reduction (Taylor, nd Chemical Metallurgical Engineering, v.44 (1937) 588, fully included here by reference). The recovery of the intermediate obtained by the decarboxylation of D-factoranalysis (acid), gives a mixture of xylitol and D-arabinitol. Xylitol can be collected using crystallization (De Faveri et al., J. Food Engineering 61 (2004) 407, included here by reference.

Figure 3 shows a detailed diagram of chemical reactions for various chemical compounds that can be used in the methods of production of xylitol by the reaction schemes in figure 2. The source material or the material of the precursor (1) can be any suitable compound that can be chemically modified by formation of substrate reagent (2), which undergoes electrochemical oxidative decarboxylation (in). As noted above, suitable source material or material precursor may include any D-glukuronidirovaniu group or D-fracturesfeeling group without replacement of oxygen in the 6th position. Source material (1) or material predecessor (if applicable), which becomes a reactant substrate is preferably the salt of D-glucuronic acid (1 in figure 2) or a glycoside, an oligomer or polymer of the above either of natural origin or obtained through oxidation. Two examples of suitable natural materials applicable as the material of the precursor or starting material, are luwaran (gluuoran) and glucurono (polymer of glucuronic acid of natural origin). Other suitable connections of the source material (1) include glucosides (R = alkyl or aryl group), compounds with residues of D-glucopyranosyl, United glycosidic bond, such as Malta or cellulo-oligo - or polysaccharides (R and/or one of R' groups = remainder D-glucopyranosyl, the other R' group = N), D-glyukopiranozil-phosphate (R = phosphate), D-glyukopiranozil-fluoride (OR=F) or sucrose (R = rest D-fructofuranosyl). Source material (1) can be either alpha or beta configuration at the carbon atom number is 1. On the other hand, oligo - or polysaccharides comprising residues D-fructofuranosyl, United by type 2,1, can also serve as source material. In another aspect of the salt compounds containing D-fructofuranosyl or its oligomer or polymer with 2.1-links obtained by the oxidation of fructan from 2.1-ties or derived from oligomers can also serve as a reagent substrate in a sequence of reactions.

Figure 3 source material (1) is transferred to a suitable substrate reagent (2), as described above relative to the reaction schemes in figure 2. The substrate reagent (2) of the aglycone glycoside (R) is preferably a chemical element selected from the group consisting of alkyl or aryl alcohol, sugar and mod is and glucopyranosyl (oligo - or polyglycerol acid) or similar protective group at carbon 1 balance glucuronidase. The remaining stages of the scheme of chemical reactions in figure 3, including oxidative decarboxylation (in) for connection of the intermediate synthesis of xylitol (3) and the reaction of hydrogenation of (e) for the production of xylitol (4), carried out as described in the reaction schemes shown in figure 2. Preferably the reagent substrate is uronic acid and intermediate for the synthesis of xylitol (3) is dialdehydes as intermediates for the synthesis of xylitol.

In the first preferred aspect of the first implementation method for the production of xylitol includes the following steps: providing a source material containing D-glyukopiranozil, oxidation of the source material containing D-glyukopiranozil, in whatever way is appropriate for formation of a reagent substrate including balance D-glucuronidase, electrochemical decarboxylation reagent substrate including balance D-glucuronidase, for the formation of the intermediate of synthesis of xylitol; restoration and hydrogenation of the intermediate synthesis of xylitol in whatever way is appropriate for the production of xylitol. Preferably, the oxidative decarboxylation is conducted through the anode of the electrochemical process. Also preferably, the intermediate of the synthesis of xylitol was non-ionic compound. In one aspect, the intermediate xylitol is D-Xylo-Penta-1,5-di is zoé.

In another preferred aspect of the first implementation of the method of producing xylitol includes the following steps: providing a source material containing D-glyukopiranozil, oxidation of the source material containing D-glyukopiranozil, in whatever way is appropriate for education material predecessor, including balance D-glucuronidase, hydrolysis of the material predecessor, including balance D-glucuronidase, in whatever way is appropriate for the formation of substrate reagent comprising a residue of D-glucuronic acid, electrochemical decarboxylation of the substrate reagent containing a residue of D-glucuronic acid, with the formation of the intermediate of synthesis of xylitol; restoration and hydrogenation of the intermediate synthesis of xylitol in whatever way is appropriate for the production of xylitol. Preferably, the oxidative decarboxylation is conducted through the anode of the electrochemical process. Also preferably, the intermediate of the synthesis of xylitol was non-ionic compound. In one aspect, the intermediate xylitol is D-Xylo-Penta-1,5-diazol.

In the third preferred aspect of the first implementation of the method of producing xylitol includes the following steps: providing a source material containing D-factoranalysis without replacement of the oxygen in the sixth position, OK is slena source material, containing D-fructofuranosyl, in whatever way is appropriate for formation of a reagent substrate including balance D-factoranalysis, hydrolysis of the material predecessor, including balance D-factoranalysis, and oxidative decarboxylation of material predecessor, with the remaining D-factoranalysis, for the production of xylitol. Preferably, the oxidative decarboxylation is conducted through the anode of the electrochemical process.

While the preferred aspects of the first implementation is presented in relation to individual molecular structures, many other reagents, substrates, materials predecessor and source materials are also considered. For example, electrochemical oxidative decarboxylation can be applied to any connection, including balance of uronic acid to produce other materials predecessor. The remains of the D-fructofuranosidase, United by type 2,1, such as can be obtained by oxidation of the primary alcohol group (carbon-6 of inulin, Yulyevich oligosaccharides or other fructans from 2.1-links) in the same way that oxidizes compounds containing residues of D-glucopyranosyl, can undergo the same fundamental (basic) the sequence of reactions leading to carbocation (CT ion is one) furan. Subsequent addition of hydroxyl and disclosure cycle and the release of give the intermediate, which can be restored to a mixture of xylitol and L-arabinitol. The isomerization of L-arabinitol leads to a mixture of epimeres alditol, which include xylitol (US patents No. 5714602 and 6458570, both of which are included here by reference). Xylitol can also be obtained biochemically from other pentelow (patent EP No. 421882, US patents No. 6303353 and 6340582, Japan patent No. 2004024140).

In one aspect of the first implementation of the method of producing xylitol includes the following steps: providing a source material containing D-factoranalysis without replacement of the oxygen in the 6th position, the oxidation of the source material containing D-factoranalysis, in whatever way is appropriate for the formation of compounds D-factoranalysis, decarboxylation material predecessor with obtaining the intermediate of synthesis of xylitol and D-arabinitol and recovery predecessor xylitol for obtaining xylitol together with D-arabinitol. Preferably, the oxidative decarboxylation is conducted through the anode of the electrochemical process.

Synthesis of xylitol containing chemical oxidative decarboxylation

In the second implementation, shown schematically in figure 4, processes for the production of xylitol include the step of oxidizing the deck is bocellimania, held by one or more chemical reactions. You can apply various chemical reactions for carrying out the oxidative decarboxylation of the substrate reagent according to the second implementation.

Methods for producing xylitol comprising the use of chemical reactions for the stage decarboxylation, is shown schematically in figure 4. Figure 4 presents two alternative process for production of xylitol second implementation. In the first aspect of xylitol produced from substrate reagent D-glucuronic acid (30), which undergoes a chemical decarboxylation (B2). In the second aspect of xylitol produced from substrate reagent L-gulonovoy acid (60), which undergoes a chemical decarboxylation (I) with the formation of the intermediate of synthesis of xylitol. The resulting intermediate of the synthesis of xylitol depends on the reagent substrate was used. In the first aspect as an intermediate for the synthesis of xylitol (40) produce D-Xylo-Penta-1,5-diosa (G2). In the second aspect as an intermediate for the synthesis of xylitol (70) receive L-xylose (Z2). Intermediates for the synthesis of xylitol (40), (70) can be restored by the hydrogenation reaction (2).

Any suitable source material can be turned into a reagent substrate, which can be used as a reagent substrate or material predecessor. Connection Chapter is koperasi (10) is shown as the starting material for the processes in figure 4. The source material can oxidize (A2) to connect glucopyranoside acid (20) by means of any suitable oxidation reaction, as described with regard to the methods of synthesis of xylitol first implementation for the formation material of the precursor or substrate reagent. The oxidation reaction (A2) material predecessor (10) to the material predecessor glucopyranoside acid (20) can be made by methods known in the art, including, but not limited to oxidation by air/About2on the catalyst, such as platinum, stable radicals nitroxyl (for example, TEMPO with regeneration) oxidation of ions of transition metals with electrochemical regeneration and electrochemically. Suitable oxidation reaction (A2) for use in the oxidation of compounds D-glucopyranosyl to residues D-glucuronidase described in the following references, which are incorporated here by reference in its entirety: .Heyns et al, "Selective catalytic oxidation of carbohydrates, employing platinum catalysts," Advances in Carbohydrate Chemistry and Biochemistry, 17, 169-221 (1962); .Yamada et al., Air oxidation of cyclodextrin with a platinum catalyst," Journal of Applied Glycoscience, 47, 21-26 (2006); P.L.Bragd et al., "Selective oxidation of carbohydrates by 4-AcNH-TEMPO/peracid systems," Carbohydrate Polymers, 49, 397-406 (2002); K.Yasuda et al., "The simultaneous use of immobilized reagents for the one-pot conversion of alcohols to carboxylic acids," Journal of the Chemical Society, Perkin Transactions, 1, 1024-1025 (2002).

Glucopyranoside to the slot (20) can be used as the material of the precursor, which can be turned into a reagent substrate or other material predecessor. Glucopyranoside acid (20) can be converted to D-glucuronic acid (30) via hydrolysis (62) material predecessor glucopyranoside acid (20). Hydrolysis of (62) material predecessor glucopyranoside acid (20) can be performed in any suitable way, as for example, by using an enzyme, such as α - and/or β-glucuronidase, or using an acid when heated. Glucuronic acid (30) can be separated from non-ionic sugars using ion-exchange chromatography.

D-glucuronic acid (30) can serve as a reagent substrate and undergo chemical decarboxylation (B2). Otherwise, D-glucuronic acid (30) preferably serves as a material of the precursor, which is then restored (E2) by means of a suitable dehydrogenation reaction with the formation of substrate reagent L-gulonovoy acid (60). The reagent substrate D-glucuronic acid (30) can be restored by a method known in the art. Suitable hydrogenation reactions include the use of hydrogen and a hydrogenation catalyst, for example, as described above for recovery (2) intermediate for the synthesis of xylitol (4) figure 2.

The reagent substrate D-Galanova acid (30) may undergo appropriate typemessage oxidative decarboxylation of (B2) with the output of the first intermediate of the synthesis of xylitol (40) D-Xylo-Penta-1,5-diose (G2). Similarly, the reagent substrate L-Galanova acid (60) may undergo any suitable type of oxidative decarboxylation (I) with the output of the second intermediate synthesis of xylitol (2) (L-xylose). The reaction of oxidative decarboxylation usually result in the release of carbon dioxide and formation of intermediates for the synthesis of xylitol, such as D-Xylo-Penta-1,5-diaza (G2) or L-xylose (g). These non-ionic intermediates for the synthesis of xylitol (40) and (70) can be separated from unreacted starting material by using anion-exchange chromatography.

Oxidative decarboxylation (B2) (I) can be carried out with the reagent on the substrate (30), applying various chemical reactions. Examples of suitable methods of oxidative decarboxylation include, but are not limited to, one or more of the following: application of transition metal ion as a catalyst with the primary oxidizing agent, the use of hypochlorite/hypochlorous acid, photochemical reactions of Gopher-Space and the use of supercritical water.

In one aspect, the chemical oxidative decarboxylation is carried out with the use of hypochlorite/hypochlorous acid. Preferably the chemical oxidative decarboxylation is carried out with the reagent on the substrate, including α-hydroxy acid, such as D-glucuronic acid or L-Galanova the acid. Amides of sugar acids can also be decarboxylate hypochlorite (degradation Hoffman). The Hoffman degradation can also be used for decarboxylation of glucuronoside. Further details on the oxidative decarboxylation of hydrocarbons with the use of hypochlorite/hypochlorous acid are R.L.Whistler et al., "Preparation of D-arabinose and D-glucose with hypochlorite", J. Amer. Chem. Soc., 81, 46397 (1981), which is incorporated here by reference.

Chemical oxidative decarboxylation can also be carried out using supercritical water, for example, as described in V.DiTullio et al., "Supercritical water refining of petroleum residues and simultaneous hydrolysis-decarboxylation of waste possesses anti-inflammatory properties, fats and proteins", PCT International Application Publication No. WO 2002/74881 (Int'l filing date September 26, 2002) (Chemical Abstracts 137, 265376 (2002)), which is incorporated here by reference in full.

In another aspect, the chemical oxidative decarboxylation is carried out with the use as catalysts of transition metal ions, such as Fe(III), Cu(II), Ru(III), Co(II), Mn (III), Ag(I), Bi(III)/Bi(0) and their complexes with primary oxidizing agents such as hydrogen peroxide, hypochlorite, hypochlorite/bromide, hypobromite, chlorine dioxide, oxygen, ozone, peroxynitrite, persulfate or bromine for catalyst regeneration.

Preferably, the production method of xylitol comprises carrying out the oxidative decarboxylation using the quality of the ve catalyst transition metal ions of copper, such as Cu(II), in combination with a suitable primary oxidant. For example, it is possible to degradation by Ruffa, preferably using ions of copper, not iron for degradation by Ruffa acidic sugars. Decarboxylation using Cu(I)/oxygen aliphatic and (α-hydroxy acids in organic solvents can be used in one aspect. In another aspect of salt Cu(III) and iodic acid (periodic) and tellurium acids (tellurate) can be used for decarboxylation (α-hydroxyacids with the release of aldehydes and ketones. Degradation by Ruffa described in W.Pigman et al., "The Carbohydrates", AR, New York, 2ndEd., v. IA (1972), v. IB (1980), part of which related to the oxidative decarboxylation of hydrocarbons, included here by reference.

Chemical oxidative decarboxylation can also be carried out with the use of the catalyst Ru(III) in combination with a suitable primary oxidant, described above, for example, as described in Y.R.Rao et al., "Kinetics of ruthenium (III)-catalyzed oxidative decarboxylation of some aliphatic acids by cerie sulfate", Proc. Natl. Symposium on Catalysis, 4th, 341-346 (Chemical Abstracts 94, 46397 (1981)), which is incorporated here by reference.

Alternative chemical oxidative decarboxylation can be carried out with the use of the compound Ce(IV), for example, decarboxylation of D-gluconic acid from D-arabinose. Acetate of lead(IV) can also be used in which takziah decarboxylation, for example, for selective cleavage glucuronoside connections, as is known in the art.

Various suitable transition metal ions can be used for decarboxylation (α-hydroxyacids, following the mechanism of decarboxylation by Gopher. For example, the chemical reaction of decarboxylation can be also decarboxylation reactions in the style of Flask/Gopher-Space, by using one or more of the following: Pb(IV), Ag(II), Mn(III), Co(III), Ce(IV) or Th(III). Other examples include the use of one or more compounds comprising ions Ni(II) or Ti(IV) in the degradation of the Ruff. Other connections that are applicable for the oxidative decarboxylation include compounds comprising one or more of the following: Au(III), Pt(IV), Ir(IV), Ag(II) and Hg(II), as is known in the art. For decarboxylation of compounds pyranose preferred methods of oxidative decarboxylation include ways degradation Hoffman and methods that include the use of compounds containing Pb(TV).

Photochemical options response of Gopher-Space can also be used for oxidative decarboxylation. Photooxidative possible actions involve titanium oxide (to which may be added Fe, Cu, Ag or other metal ions) or iron(III)-porphyrin complexes. Further details of these gloves is a scale photochemical oxidative decarboxylation are found in the following sources, included here in full: J.M.Hermann et al., "Photocatalytic degradation of aqueous hydroxyl-butandioic acid (malic acid) in contact with powdered titania and support in water," Catalysis Today, 54, 131-141 (1999); P.Hanson et al., "The mechanisms of the photo-decarboxylation of alkyl-and arylmethyl-carboxylates using visible light and iron (III) tetra(2-N-methylphyridyl) porphrin pentachloride in aqueous solution," Journal of the Chemical Society, Perkin Transactions, 2, 2653-2568 (1998).

Referring again to figure 4, where the first intermediate of the synthesis of xylitol (40), shown as D-Xylo-Penta-1,5-diaza (G2), or a second intermediate of the synthesis of xylitol (70), shown as L-xylose (Z2), you can restore (2) using hydrogen and a hydrogenation catalyst to obtain xylitol (50). Recovery (2) can be performed using any suitable reaction, such as ruthenium or Nickel catalysis. For example, recovery (2) may be a reaction of hydrogenation is carried out with hydrogen and a ruthenium (see patent application WO No. 2004052813 included here by reference), Nickel (US patent No. 4008285 included here by reference) or other hydrogenation catalysts known in the art for obtaining xylitol (50). In one aspect, the hydrogenation can be conducted at temperatures between 70°C and 150°C and at a pressure between 0.1 and 10 MPa H2. Alternatively, you can apply electrochemical reduction (Taylor, Chemical and Metallurgical Engineering, v.44 (1937) 588, which is incorporated here by reference). In one aspect, the intermediate of the synthesis of Csile is a (40) D-Xylo-Penta-1,5-diosa (G2) and/or intermediate of the synthesis of xylitol (70) L-xylose (g), you can recover hydrogen and ruthenium.

After recovery (g) xylitol (50) can be obtained from the final product by crystallization, for example as described in De Faveri et al., J. Food Engineering 61 (2004) 407, which is incorporated here by reference in full. L-xylose (70) can be separated from unreacted salts of L-gulonovoy acids using anion-exchange chromatography. Xylitol can be separated from L-gulonovoy and D-glucuronic acid in any suitable way, including ion-exchange chromatography. In one especially preferred aspect, L-golosovoy acid ionized salt form oxidized with the release of L-xylose and decarboxylases D-glucuronic acid with the release of MDA, both these product can be restored to obtain xylitol.

Figure 5 presents the sequence of reactions described in figure 4, when the source material (10) is the link α-D-glucopyranosyl associated glycosidic bond, or related compounds and a reagent substrate is D-glucuronic acid (30). Figure 5 source material (10) is oxidized (A2) to the material predecessor (20) (for example, connection glucopyranoside acid), which is hydrolyzed (62) to the substrate reagent D-glucuronic acid (30). Chemical oxidative decarboxylation (B2) substrate reagent D-glucuronic acid (30) leads to the intermediate synthesis of xylitol to dialdehyde (40), which is output can be restored to xylitol (50). Preferably intermediate of the synthesis of xylitol (40) is a dialdehyde.

6 represents the sequence of reactions figure 4, when the connection D-glucuronic acid (30) is a material of the predecessor, which is restored (E2) to L-gulonovoy acid (60). L-Galanova acid (60) undergoes decarboxylation to obtain the intermediate of the synthesis of xylitol L - xylose (70)that can be recovered (2) to xylitol (50).

Preferably the compound D-glucuronic acid (30) is a salt, including sodium, potassium, ammonium, calcium and/or magnesium salt of oligo - or poly(glucuronic acid) (degree of polymerization of 2 or higher). More specifically, the compound D-glucuronic acid (30) may be a salt of D-glucuronic acid, alkyl or aryl D-glucuronoside, D-glucuronosyl-1-phosphate and glucuronidase-fluoride. The reagent substrate (30) may also be a connection D-factoranalysis, if necessary, including sodium, potassium, ammonium, calcium and/or magnesium salts of oxidized inulin or other fructan communication of 2.1. Salt L-gulonovoy acid (60) preferably includes at least one of the group consisting of sodium, potassium, ammonium, calcium and/or magnesium salt of L-gulonovoy acid.

With reference to figure 5 and 6, the source material (10) or material predestiny is or can be a connection, which includes glucosides (R= alkyl or aryl group), other compounds with residues of D-glucopyranose, United glycosidic linkages, such as Malta or cellulo-oligo - or polysaccharides (R and/or one of R' groups = α-D-glyukopiranozil, the other R' group = N), D-glyukopiranozil-phosphate (R= phosphate), D-glyukopiranozil-fluoride (OR=F) or sucrose (R=link D-fructofuranosyl). Hydroxyalkyl group (OR), the first carbon source material (10) can be in either the α-or β-configuration. If necessary, the source material (10) can be natural glucuronides or sucrose, oxidized to activate the rest of D-glucuronic acid. The source material can also be obtained by oxidation of the alkyl-glucoside, D-glucose-1-phosphate or D-glyukopiranozil-fluoride to the corresponding compounds containing D-glucuronic acid, starch, dextrin, maltodextrin or other derivatives of starch to compounds containing multiple residues of D-glucuronic acid by the oxidation of cellulose or allocstring to compounds containing multiple residues of D-glucuronic acid; sucrose with getting the rest of glucuronic acid. The source material can also be glucuronides of natural origin.

The reagent substrate (20) in figure 5 is preferably D-glucuronic acid or a glycoside, Oleg the mayor or a polymer of the above or related compound or in the form of natural material, or obtained through oxidation. The reagent substrate (60) 6 is preferably a compound L-gulonovoy acid. Intermediate of the synthesis of xylitol (40) figure 5 (after oxidative decarboxylation of D-glucuronic acid and glycosides or related compounds) or the intermediate of the synthesis of xylitol (60) 6 (after oxidative decarboxylation of D-glucuronic acid) can be restored (D2) with the release of xylitol (50). Recovery (2) can be performed in any suitable manner, including those described in relation to step (d) recovery of the intermediate synthesis of xylitol in figure 2 the first implementation.

In one aspect of the second implementation of the method of producing xylitol includes the following steps: providing a source material containing D-glyukopiranozil, oxidation of the source material containing D-glyukopiranozil, any suitable method for the formation material of the first predecessor, including link D-glucuronidase, hydrolysis of the first material predecessor in whatever way is appropriate for the formation of the second material precursor comprising D-glucuronic acid, restore, and hydrogenation of the second material precursor in any suitable way with the formation of substrate reagent comprising L-golosovoy acid, oxidative decarboxylase is the W of substrate reagent, includes L-golosovoy acid, to obtain the intermediate of the synthesis of xylitol, recovery and hydrogenation of the intermediate synthesis of xylitol in whatever way is appropriate for the production of xylitol. Preferably the intermediate synthesis of xylitol is L-xylose.

An alternative aspect of the second implementation provides a method of producing xylitol comprising the following steps: providing a source material containing D-glyukopiranozil, oxidation of the source material containing D-glyukopiranozil, any suitable method for the formation of material predecessor, including link D-glucuronidase, hydrolysis of the material predecessor, including link D-glucuronidase, in whatever way is appropriate for formation of a reagent substrate comprising D-glucuronic acid, oxidative decarboxylation reagent substrate comprising D-glucuronic acid, to obtain the intermediate of the synthesis of xylitol, recovery and hydrogenation of the intermediate synthesis of xylitol in whatever way is appropriate for the production of xylitol. In this aspect, the intermediate of the synthesis of xylitol is generally D-Xylo-Penta-1,5-diose.

Another aspect of the second implementation provides a method of producing xylitol comprising the following steps: providing a source material containing D-glyukopiranozil, Islena source material, containing D-glyukopiranozil, any suitable method for the formation of material predecessor, including link D-glucopyranoside acid, hydrolysis of the material predecessor, including link D-glucopyranoside acid, in whatever way is appropriate for formation of a reagent substrate comprising D-glucuronic acid, oxidative decarboxylation reagent substrate comprising D-glucuronic acid, to obtain the intermediate of the synthesis of xylitol, recovery and hydrogenation of the intermediate synthesis of xylitol in whatever way is appropriate for the production of xylitol. In this aspect, the intermediate is generally D-Xylo-Penta-1,5-diose.

Methods of production of xylitol give an output of approximately 20, 30, 40, 50, 60, 70, 80, 85, 90, 95 or up to 100% of theoretical yield, more preferably not less than about 40%, at least about 60%, at least about 80%, or preferably not less than about 95% of theoretical yield.

Preferably also, the methods of production of xylitol consume not less than approximately 20, 30, 40, 50, 60, 70, 80, 85, 90, 95 or up to 100% of the source material in a molar ratio, and more preferably, consume no less than about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, not less arr is siteline 95% or more of the source material in molar ratio. In some implementations unreacted starting material re-use through the application of unreacted starting material as a starting material for the reaction, the material of the precursor or substrate reagent.

Illustrative combinations of aspects of the implementation are described below. In relation to methods of synthesis of xylitol first implementation is particularly preferably an electrochemical oxidative decarboxylation of the substrate reagent, including the structure of pyranose or furanose cycle. In one aspect, the reagent substrates oxidative decarboxylation are compounds comprising D-glukuronidirovaniu group without chemical substitution of oxygen in the 6th position of the pyranose cycle. In another aspect, the reagents are substrates for oxidative decarboxylation are substances, including D-fracturesfeeling group without chemical substitution at oxygen furanosyl cycle. In relation to methods of synthesis of xylitol second preferred implementation of the reaction, including the steps of hydrolysis of compounds, including D-glyconanoparticles link, liberating free D-glucuronic acid and subsequent recovery to L-gulonovoy acid. Restoration with metal ions as catalysts, particularly copper (in the example, degradation by Ruffa), preferably for recovery of D-glucuronic acid to L-golosovoy acid. Several separate illustrative combinations of aspects of the first and second implementation is shown below.

In the first illustrative aspect, the production method of xylitol includes one or more of the following steps:

a) decarboxylation of D-glucuronic connection electrochemically to obtain the dialdehyde as intermediate for the synthesis of xylitol,

b) hydrogenation of the intermediate synthesis of xylitol in the presence of a catalyst for the production of xylitol,

C) if necessary, the separation of the intermediate synthesis of xylitol from unreacted salt uronic acid or a glycoside, their oligomers or polymers and related compounds,

g) if necessary, re-use of any unreacted starting material in step a).

In the second illustrative aspect, the production method of xylitol includes one or more of the following steps:

a) decarboxylation of salt D-fracturesfeeling acid or glycoside, oligomer or polymer electrochemically to get dicarbonyl intermediate for the synthesis of xylitol,

b) hydrogenation of the intermediate synthesis of xylitol in the presence of a catalyst to obtain a mixture of xylitol and D-arabinitol,

C) if necessary, the office online is rmediate from unreacted salt D-fracturesfeeling acid or glycoside, their oligomers or polymers; or

g) if necessary, further including re-use of remaining starting material in step a).

In the third illustrative aspect of the production method of xylitol includes one or more of the following steps:

a) decarboxylation of salt D-gulonovoy acid electrochemically to get L-xylose,

b) hydrogenation of L-xylose in the presence of a catalyst for the production of xylitol,

C) if necessary, separation of L-xylose or xylitol from unreacted salts of L-gulonovoy acid,

g) if necessary, re-use of any unreacted starting material in step a).

In the fourth illustrative aspect of the production method of xylitol include a step of dissolving salt uronic acid or its glycoside in a suitable mixing with the water solvent, such as water, methanol, ethanol, dioxane or acetonitrile.

In the fifth illustrative aspect of the production method of xylitol includes the step of electrochemical decarboxylation. Preferably, the oxidative decarboxylation occurs inside the electrochemical cell at the anode. More preferably, the anode includes the spectral pure graphite, pyrolytic carbon, graphite, wax impregnated, vitreous carbon, dispersed graphite, dispersed of carbon is materials, carbon fabric, coke or platinum in the form of a packaged basis, diluted basis or porous anode. It is preferable that the reduction occurs at the cathode in the electrochemical cell.

In the sixth illustrative aspect, a method of producing xylitol includes the step of catalytic hydrogenation/restore, if necessary, by using a ruthenium, Nickel of Renee or other hydrogenation catalysts.

In the seventh illustrative aspect, a method of producing xylitol includes one or more of the following steps:

a) recovery of D-glucuronic acid to L-gulonovoy acid,

b) decarboxylation of salt L-gulonovoy acid to obtain L-xylose,

b) hydrogenation of L-xylose in the presence of catalytic hydrogenation for the production of xylitol, if necessary, by applying ruthenium, Nickel or other hydrogenation catalysts,

g) optionally, separation of L-xylose from unreacted L-gulonovoy acid; or

d) if necessary, re-use of L-guanata phase b).

L-Galanova acid optionally may be provided in the form of sodium, potassium, ammonium, calcium and/or magnesium salt.

In the eighth illustrative aspect of the production method of xylitol includes conducting phase chemical oxidative decarboxilation is one or more of the following ways:

a) application of catalysis ions of transition metals such as Fe(III), Cu(II), Ru(III), Co(II), Mn(III), Ag(I) or Bi(III)/Bi(0);

b) application of transition metal complexes;

C) applying a primary oxidant, such as hydrogen peroxide, hypochlorite/hypochlorous acid, hypobromite/bromoviridae acid, hypochlorite/bromide, chlorine dioxide, oxygen/air, ozone, peroxynitrite or persulfate;

g) the use of photo-oxidative decarboxylation applied to titanium oxide, the titanium dioxide with addition (additive) Fe, Cu, Ag or other metal ions, or oxide of titanium with the additive of the complex Fe(III)-porphyrin or other complexes with metal ions; or

d) application of hypochlorite/hypochlorous acid or hypobromite/bromoviridae acid.

In the ninth illustrative aspect of the production method of xylitol includes one or more of the following steps:

a) hydrolysis of compounds containing link D-glucuronic acid,

b) decarboxylation salt of D-glucuronic acid to produce dialdehyde intermediate for the synthesis of xylitol, and

b) hydrogenation of the intermediate synthesis of xylitol in the presence of a catalyst for the production of xylitol,

g) if necessary, the separation of the intermediate synthesis of xylitol from unreacted salt uronic acid,

d) if necessary popcorn the e use of remaining starting material in step b).

EXAMPLES

The following examples are only illustrative and should not be interpreted as limiting since further modifications of the disclosed implementations will be obvious to a person skilled in the art in view of these instructions. All these modifications are covered by the scope of application implementations disclosed here.

Example 1:

Electrochemical decarboxylation of salt D-glucuronate monohydrate to obtain xylitol

The sodium glucuronate dnovotny (2,69 g, 0,0115 mol) is dissolved in 43 ml of a mixture methanol/water (46.2 wt.%). The solution is electrolyzed in a one-compartment cell with a graphite anode at a constant voltage 9.99 per period or 4.31 watt-hours. The electrolyte solution is then adjusted to 110 ml of a mixture of ethanol/water (50%) and hydronaut by adding Nickel of Renee and passing hydrogen gas at 1 ATM at 50°C. the Resulting hydrogenated syrup contains 0.87 g of xylitol (50% of theoretical yield) and 1.10 g of L-guanata sodium (42% of the source material in a molar ratio).

Theoretical output or "% of theoretical yield" is calculated as follows:

First, define the following molecular weights:

a) D-glucuronate, sodium monohydrate 235

b) methyl-β-D-glucuronate, sodium 231

in) L gulonic sodium 219

g) xylitol 152

Next, calculate as follows: 2,69 g source the th material is 0,0114 mole and theoretical yield of xylitol is 0,0114×152, i.e. 1,74, Real output is 0.87 g, which is 50% of theoretical yield.

Example 2:

Electrochemical decarboxylation salts of alkyl-β-D-glucuronoside to obtain xylitol

Methyl-β-D-glucuronoside sodium (2,52 g, 0,0103 mol) is dissolved in 39 ml of water. The solution is electrolyzed in a one-compartment cell with a graphite anode at a constant voltage of 9.99 volts for 8,49 watt-hours. The electrolyte solution is then adjusted to 110 ml of a mixture of ethanol/water (50%) and hydronaut by adding Nickel of Renee and passing hydrogen gas at 1 ATM at 50°C. the Resulting hydrogenated syrup contains 0,70 g of xylitol (42% of theoretical yield).

Example 3:

Electrochemical decarboxylation salt of L-guanata to obtain xylitol

L-gulonic sodium (2.67 g, 0,01222 mol) is dissolved in 43 ml of a mixture of methanol-water (46.2 wt.%). The solution is electrolyzed in a one-compartment cell with a graphite anode at a constant voltage 9.99 per for 5,32 watt-hours. The electrolyte solution is then adjusted to 110 ml of a mixture of ethanol/water (50%) and hydronaut by adding Nickel of Renee and passing hydrogen gas at 1 ATM at 50°C. the Resulting hydrogenated syrup contains 0.87 g of xylitol (47% of theoretical yield) and 1.10 g of L-guanata sodium (41% of the source material, in molar ratio).

Example 4:

Cu(II) - dekarboksilirovanie L-guanata to obtain xylitol

L-Gulonic sodium (2.25 g, 0,0100 mol) is dissolved in 17 ml of water and add 35 mg of copper sulfate pativedha. the pH of the solution raised to 7.0 with sodium hydroxide (2M). In the course of the reaction constantly add 1.2 ml of 30%hydrogen peroxide. The pH value of support to 7.0 by adding sodium hydroxide (2M). After 13 min temperature is 44°C and the copper precipitates as an orange suspension. The reaction solution is filtered and then adjusted to 110 ml of a 50%mixture of ethanol/water, and hydronaut by adding Nickel of Renee and passing hydrogen gas at 1 ATM at 50°C. the Resulting hydrogenated syrup contains of 0.91 g of xylitol (58% of theoretical yield) and 0.72 g L-guanata sodium (32% of the source material in a molar ratio).

Example 5:

Decarboxylation salt of L-guanata with hypochlorous acid to produce xylitol

L-gulonic sodium (0,244 g of 1.12×10-3mol) is dissolved in 15 ml of water and raise the temperature to 50°C. Add 1.5 ml of 13%sodium hypochlorite solution. Add 2M hypochlorous acid to lower the pH to 5.0. The reaction is kept at 50°C and maintain at pH of 5.0 by adding 2M sodium hydroxide. After 19 min, the reaction mixture is brought to 110 ml of a 50%mixture of ethanol/water and hydronaut by adding Nickel of Renee and passing hydrogen gas at 1 ATM at 50°C. the Resulting hydrogenated syrup sod is RIT 0.16 g of xylitol (95% of theoretical yield) and 0.004 g of L-guanata sodium (2% of the source material in a molar ratio).

As described different embodiment of the invention, for ordinary experts in the art it will be obvious that other and realization are possible within the scope of application of the invention. Accordingly, the invention is limited only by the scope of the claims, as reflected in the claims and their equivalents.

1. The method of producing xylitol comprising the steps:
a) electrochemical oxidative decarboxylation of compounds of uronic acid to obtain an intermediate of the synthesis of xylitol and
b) hydrogenation of the intermediate synthesis of xylitol to obtain xylitol.

2. The method according to claim 1, where the connection uronic acid includes furanosyl or pyranose cycle.

3. The method of producing xylitol comprising the steps:
a) recovery of D-glucuronic acid to L-gulonovoy acid,
b) electrochemical oxidative decarboxylation of L-gulonovoy acid to obtain L-xylose and
b) hydrogenation of L-xylose to obtain xylitol.

4. The method according to claim 3, further comprising the step of re-use of the remaining L-gulonovoy acid.

5. A method of producing xylitol comprising the following steps:
a) hydrolysis of compound D-glucuronic acid,
b) decarboxylation of compounds of D-glucuronic acid to produce dialdehyde intermediate for the synthesis of xylitol,
in) hidri the Finance intermediate for the synthesis of xylitol in the presence of a hydrogenation catalyst to obtain xylitol.

6. The method according to claim 5, further comprising the step of separating the intermediate synthesis of xylitol from unreacted compounds D-glucuronic acid.

7. A method of producing xylitol comprising the steps:
a) providing a material containing D-glyukopiranozil,
b) oxidation of the material containing D-glyukopiranozil, with the formation material of the precursor containing the link D-glucuronidase,
C) hydrolysis of the material of the precursor containing the link D-glucuronidase, for the formation of substrate reagent containing D-glucuronic acid,
d) oxidative decarboxylation reagent substrate comprising D-glucuronic acid, to obtain the intermediate of the synthesis of xylitol and
d) recovery/hydrogenation of the intermediate synthesis of xylitol to obtain xylitol.

8. A method of producing xylitol comprising the steps:
a) providing a material containing D-factoranalysis, unsubstituted in the positions of the oxygen cycle
b) oxidation of the material containing D-factoranalysis, with the formation material of the predecessor, including link D-factoranalysis,
C) hydrolysis of the material of the precursor containing the link D-factoranalysis, and
g) electrochemical oxidative decarboxylation of material precursor containing link D-factoranalysis, the La receiving xylitol.

9. A method of producing xylitol comprising the steps:
a) electrochemical decarboxylation of compounds of D-glucuronic acid to produce an intermediate of the synthesis of xylitol and
b) hydrogenation of the intermediate synthesis of xylitol in the presence of a catalyst to obtain xylitol.

10. The method according to claim 9, further comprising the step of separating the intermediate synthesis of xylitol from unreacted compounds D-glucuronic acid.

11. The method according to claim 9, further comprising the steps of: re-application of unreacted compounds D-glucuronic acid and electrochemical decarboxylation of unreacted compounds D-glucuronic acid.

12. The method of producing xylitol comprising the steps:
a) electrochemical decarboxylation of compounds of uronic acid to obtain dicarbonyl intermediate for the synthesis of xylitol and
b) hydrogenation of the carbonyl intermediate of the synthesis of xylitol in the presence of a catalyst.

13. The method according to item 12, further comprising the separation of the intermediate synthesis of xylitol from unreacted compounds uronic acid.

14. The method according to item 13, further comprising the step of re-use of the remaining compounds of uronic acid.

15. A method of producing xylitol comprising the steps:
a) electrochemical decarboxylation of salt L-gulonovoy sour is you to obtain L-xylose and
b) hydrogenation of L-xylose in the presence of a catalyst to obtain xylitol.

16. The method according to clause 15, further comprising the step of separating L-xylose from unreacted salts of L-gulonovoy acid.

17. The method according to clause 15, further comprising reusing any unreacted salts of L-gulonovoy acid.

18. The method according to claim 1, where the connection uronic acid dissolved in a miscible with water, the solvent is selected from the group consisting of water, methanol, ethanol, dioxane and acetonitrile.

19. A method of producing xylitol comprising the steps:
a) providing a source material containing D-glyukopiranozil,
b) oxidation of the source material containing D-glyukopiranozil, with the formation material of the predecessor, including link D-glucopyranosyl,
in electrochemical decarboxylation of material precursor containing link D - glucopyranosyl, to obtain a precursor of xylitol,
g) recovery/gidrogenizirovanii predecessor xylitol for obtaining xylitol.

20. The method according to claim 19, in which a source material containing D-glyukopiranozil contains alkoxy group at C-1 carbon.



 

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FIELD: metallurgy.

SUBSTANCE: at least one nonionic surfactant in an electrolytic solution is used in electrolytic treatment of metal-containing solutions. The surfactant used reduces surface tension of the electrolytic solution by 20-60%, where the electrolytic solution has surfactant concentration of 0.2 wt % and at temperature of 24°C in an aqueous solution with 190 g/l of sulphuric acid and 157 g/l of copper sulphate, which is diluted with water in ratio of 1:10. The invention can be used for extraction or purification of metals such as copper, chromium, nickel, zinc, gold and silver.

EFFECT: prevention of fogging during extraction of acidic solutions in order to improve properties of the extracted metal.

17 cl, 2 tbl

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SUBSTANCE: cation-exchange membrane for electrolysis which includes a fluoropolymer which contains an ion-exchange group and a porous base is distinguished by that, on the surface of the anode side of the membrane there are projecting parts with a fluorine-containing polymer which contains an ion-exchange group; 20≤h≤150, where h is the average height (mcm) from the surface of the anode side of the membrane to the top of the projecting parts; 50≤P≤1200, where P is distribution density (number/cm2) of the projecting parts; 0.001≤S≤0.6, where S is the ratio of area of the bottom surfaces of the projecting parts to the total area of the anode side of the membrane; and T≤0.05, where T is the ratio of the area of the top parts of the projecting parts to the total area of the anode side of the membrane.

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9 cl, 1 tbl, 7 ex

FIELD: chemistry.

SUBSTANCE: cation-exchange membrane for electrolysis which includes a fluoropolymer which contains an ion-exchange group and a porous base is distinguished by that, on the surface of the anode side of the membrane there are projecting parts with a fluorine-containing polymer which contains an ion-exchange group; 20≤h≤150, where h is the average height (mcm) from the surface of the anode side of the membrane to the top of the projecting parts; 50≤P≤1200, where P is distribution density (number/cm2) of the projecting parts; 0.001≤S≤0.6, where S is the ratio of area of the bottom surfaces of the projecting parts to the total area of the anode side of the membrane; and T≤0.05, where T is the ratio of the area of the top parts of the projecting parts to the total area of the anode side of the membrane.

EFFECT: invention enables obtaining a membrane with stable operational characteristics with retention of electrochemical properties and mechanical strength.

9 cl, 1 tbl, 7 ex

FIELD: chemistry.

SUBSTANCE: method of making an electrode for electrochemical processes involves electrodeposition of an electrocatalytic coating based on mixed oxides of base metals on a titanium surface. The said coating on the titanium surface is formed through electrodeposition from an aqueous solution of an electrolyte which contains salts of cobalt, manganese, nickel and boric acid under the effect of alternating asymmetrical current in which the current amplitude ratio of the anode and cathode half-cycles is 2:1, at voltage of 8-10 V, with the following ratio of components (g/l): cobalt sulphate (CoSO4·7H2O) - 100.0-110.0, manganese sulphate (MnSO4·5H2O) - 20.0-25.0, nickel sulphate (NiSO4·7H2O) - 15.0-20.0, boric acid (H3BO3) - 25.0-30.0, with subsequent thermal treatment in an oxidising atmosphere at 350-380°C for 30 minutes.

EFFECT: invention increases corrosion resistance and electrocatalytic activity of the electrode, increases bonding strength of the coating with the titanium substrate, reduces the cost of making the electrode and energy consumption of the process.

1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: method of making an electrode for electrochemical processes involves electrodeposition of an electrocatalytic coating based on mixed oxides of base metals on a titanium surface. The said coating on the titanium surface is formed through electrodeposition from an aqueous solution of an electrolyte which contains salts of cobalt, manganese, nickel and boric acid under the effect of alternating asymmetrical current in which the current amplitude ratio of the anode and cathode half-cycles is 2:1, at voltage of 8-10 V, with the following ratio of components (g/l): cobalt sulphate (CoSO4·7H2O) - 100.0-110.0, manganese sulphate (MnSO4·5H2O) - 20.0-25.0, nickel sulphate (NiSO4·7H2O) - 15.0-20.0, boric acid (H3BO3) - 25.0-30.0, with subsequent thermal treatment in an oxidising atmosphere at 350-380°C for 30 minutes.

EFFECT: invention increases corrosion resistance and electrocatalytic activity of the electrode, increases bonding strength of the coating with the titanium substrate, reduces the cost of making the electrode and energy consumption of the process.

1 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: according to method water is treated in electrolytic way, also there is ion changing substance present in water containing matrix, anchor groups and changeable ions. The facility for implementation of the method consists of a reservoir with water wherein an ion changeable substance is present, of a positive electrode and negative electrode which can be attached or attached to a current source.

EFFECT: improved methods of hydrogen and oxygen production.

4 cl, 1 dwg, 3 tbl, 3 ex

FIELD: metallurgy.

SUBSTANCE: according to method water is treated in electrolytic way, also there is ion changing substance present in water containing matrix, anchor groups and changeable ions. The facility for implementation of the method consists of a reservoir with water wherein an ion changeable substance is present, of a positive electrode and negative electrode which can be attached or attached to a current source.

EFFECT: improved methods of hydrogen and oxygen production.

4 cl, 1 dwg, 3 tbl, 3 ex

FIELD: metallurgy.

SUBSTANCE: according to method water is treated in electrolytic way, also there is ion changing substance present in water containing matrix, anchor groups and changeable ions. The facility for implementation of the method consists of a reservoir with water wherein an ion changeable substance is present, of a positive electrode and negative electrode which can be attached or attached to a current source.

EFFECT: improved methods of hydrogen and oxygen production.

4 cl, 1 dwg, 3 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to organic chemistry, more specifically to a method of producing 2-aminoethanesulfonic acid by reacting 2-aminoethylsulphuric acid with excess sodium sulphate in an aqueous solution and boiling for 20 hours with subsequent separation of the desired product from mineral salts through electrodialysis at temperature 30-45°C and constant current density of 1.2-3.0 A/dm2.

EFFECT: reduced power consumption of the process and intensification of the technology with high current output of the product.

1 cl, 4 ex

FIELD: metallurgy.

SUBSTANCE: method of fabrication of electrode for electrolysis of water solutions of alkali metal chlorides consists in preliminary treatment of electrode titanium base surface, in application coating onto it, where coating consists of thermo-decomposed compounds of titanium, iridium and ruthenium; further the method consists in their succeeding thermal treatment in oxidising atmosphere and in producing electro-catalytic coating containing oxides of titanium, iridium and ruthenium; also surface of electro-catalytic coating is additionally treated with 20-25% water solution of hydrogen peroxide by means of sputtering it at amount of 80-140 g/m2 and successively heat treated at temperature of 450-480°C.

EFFECT: raised resistance of electrode, increased service life.

5 cl, 4 tbl

FIELD: chemistry.

SUBSTANCE: method of separating multi-atom alcohols, for instance, neopentylglycol and sodium formiate, includes evaporation and cooling of reaction mixture, addition of organic solvent, crystallisation of sodium formiate, separation of sodium formiate from saturated solution of multi-atom alcohol, for instance, by filtration, and crystallisation of multi-atom alcohol. Reaction mixture is evaporated until two liquid layers are formed, which are separated into light phase - water-multi-atom alcohol and heavy phase -water-salt, separated water-salt fraction of solution is cooled until sodium formiate contained in it in form of cryslallohydrate is crystallised, sodium formiate crystals are separated, and remaining mother-solution is returned to process head, to evaporation stage, then separated light phase - water-multi-atom alcohol is additionally evaporated until 70% of contained in it sodium formiate is crystallised, then cooled to 25-30°C and subjected to processing with organic solvent from line of single-atom saturated alcohols, for instance, methane, for removal of remaining admixtures, with further crystallisation of multi-atom alcohol from remaining mother-solution.

EFFECT: reduction of amount of used organic solvent, elimination of high-temperature stage of extraction, preservation of yield of pure target products.

2 cl, 2 dwg, 1 ex

The invention relates to an improved process for the preparation of pentaerythritol with a basic substance content of more than 98 wt.% and pentaerythritol, enriched dipentaerythritol in the amount of 5-20 wt.%, used in paint and other industries

The invention relates to the production of xylitol

The invention relates to the production of xylitol

The invention relates to a method of sequential simulated moving layers, in particular acceptable for fractionation of sulfate pulping solution at least three fractions
The invention relates to methods for complex diesters of terephthalic acid and diodes of polyesters

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing glycol aldehyde, involving reaction of formaldehyde with hydrogen and carbon monoxide in the presence of a catalyst composition, which is based on a) rhodium source, b) ligand with general formula R1P-R2 (I), where R1 is a bivalent radical, which, together with the phosphorous atom to which it is bonded, is 2-phospha-1,3,5,7-tetraC1-20alkyl-6,9,10-trioxatricyclo[3.3.1.1{3,7}]decile group, and where R2 is a monovalent radical, which is chosen from an alkyl group, containing 4 to 34 carbon atoms or a radical with general formula: -R3-C(O)NR4R5 (II), where R3 represents methylene, ethylene, propylene or butylene, and R4 and R5 independently represent an alkyl group containing 1 to 22 carbon atoms, and c) anion source. The invention also relates to a catalyst composition used in the production of glycol aldehyde, and to a method of producing ethylene glycol from glycol aldehyde obtained using the described method.

EFFECT: easy conversion of formaldehyde to glycol aldehyde in the presence of a stable catalyst.

6 cl, 11 ex

FIELD: chemistry.

SUBSTANCE: invention refers to method of producing 1,3-propanediol by hydrogenation of 3-hydroxypropanal (versions). The first version of the method includes the stages as follows: (a) formation of aqueous 3-hydroxypropanal mixture, (b) delivery of aqueous mixture containing 3-hydroxypropanal through hydrogenation zone wherein it includes, at least, two stages with hydrogenation at the first stage performed at temperature 50 to 130°C with static bed of suspended in the presence of a motionless layer hydrogenation catalyst, and with at least, one of last stages involves adding acid cocatalyst, or acid cocatalyst is being chosen of the group consisting of acid zeolites, acid cation-exchange resins, acid or amphoteric metal oxides, heteropolyacids, and soluble acids chosen of the group consisting of mineral acids, phosphoric acid, acetic acid, propionic acid and 3-hydroxypropionic acid, herewith hydrogenation at the specified last stages is performed at higher temperatures, than at the first stage, within 70 to 155°C, to produce 1,3-propanediol aqueous solution; and (c) release of 1,3-propanediol specified.

EFFECT: invention makes enables effective reverse reaction with improved-yield transforming acetal by-products in 1,3-propanediol.

24 cl, 3 tbl, 18 ex

FIELD: chemistry.

SUBSTANCE: method of obtaining 1,3-propandiol includes preparation of 3-hydroxypropanal water solution; removal from solution catalyst, probably used during said preparation; adding to solution hydroxide, selected from group, consisting of ammonium hydroxide, alkali metal hydroxides, alkali earth metal hydroxides, except sodium hydroxide, for neutralization of any contained in it acid in such way that pH constitutes at least 5; hydrogenating neutralised water solution in order to obtain mixture of raw 1,3-propandiol, which is subjected to distillation, obtaining 1,3-propandiol, water and reaction-able heavy components.

EFFECT: reduction of viscosity of reaction-able heavy components.

6 cl, 5 ex

FIELD: chemistry.

SUBSTANCE: invention relates to processes of catalytic hydration. Claimed is catalyst for liquid-phase hydration of organic substances of various classes i.e. nitro-compounds, aldehides, unsaturated and aromatic compounds, with molecular hydrogen, which includes unit-type carrier of low density and high porosity and metallic palladium. Carrier is made from aluminium oxide by method of doubling foam-polyurethane matrix by impregnating it with slip Al2O3 with further calcination. Layers of γ-Al2O3 are applied on carrier successively in such a way that weight of active layer from γ-Al2O3 is not less than 6% of total weight of catalyst, and of metallic palladium in amount of 0.16-3.7%. Alternatively, instead of γ-Al2O3 layer, layer of sulphated oxide of titanium or zirconium in amount of 8-9% is applied on carrier. Due to developed surface, the claimed catalyst is efficient when hydrating compounds of various classes, and has high mechanical strength, which eliminates its abrasion in the process of exploitation.

EFFECT: obtaining catalyst efficient when hydrating compounds of various classes, and having high mechanical strength, which eliminates its abrasion in the process of exploitation.

2 cl, 1 tbl, 14 ex

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