KR100842944B1 - Synthesis of c5 deprotected ribofuranosides - Google Patents

Abstract

A method for preparing ribofuranoside having a hydroxy group at C5 position is provided to save energy and be environment-friendly using an enzyme reaction, thereby being effective for constructing molecular diversity and synthesizing a precise compound. To prepare ribofuranoside having a hydroxy group at C5 position, (C1-6 alkyl)-2,3,5-tri(C1-6 alkanoyl)ribofuranoside represented by a formula(1) as a substrate is hydrolyzed at the C5 position selectively by an enzyme selected from the group consisting of lipase derived from Pseudomonas fluorescence, lipase derived from Burkholderia cepacia, lipase derived from Pseudomonas cepacia, acylase derived from Aspergillus sp., PLE(pig liver esterase), LWG(wheat germ lipase), lipase derived from Bacillus thermoleovorans, Amano lipase M and lipase derived from Alcaligenes sp., wherein the substrate is beta methyl 2,3,5-triacetyl ribofuranoside or beta methyl 2,3,5-tripropionyl ribofuranoside. In the formula(1), R^1 is C1-6 alkyl and R is C1-6 alkanoyl.

Description

Synthesis of C5 deprotected ribofuranosides having a hydroxyl group at the 5th carbon position

Figure 1 shows the molecular structure of the monosaccharides.

The present invention relates to a method for preparing ribofuranoside having a hydroxy group at the carbon position 5, and more specifically to beta C ₁ ~ C ₆ alkyl tri (C ₁ ~ C ₆ alkanoyl) ribofuranoside substrate The present invention relates to a method for producing ribofuranoside having a hydroxyl group at a carbon position by selectively hydrolyzing at a carbon position with a specific enzyme.

Carbohydrates are compounds that are abundant in nature such as proteins, lipids, and hexanes. Not only can they be used as the basis for the preparation of precise compounds chemically, but they also play an important role in the biological activity of cells within cells and between cells. In particular, the monosaccharides of carbohydrates also serve as building blocks of the polymeric compounds of life. Examples of these are constituents of glyco-conjugated natural product complexes such as glyco- lipids, glyco-proteins, glyco-peptides.

Carbohydrates of monosaccharides have a three-dimensional structure by showing a ring-shaped structure containing oxygen of pentasaccharide (pentose) or hexasaccharide (hexose). In addition, they contain several hydroxyl groups, so that each positional isomer may exist and the reactivity of each hydroxyl group is very similar. These monosaccharides are representative hexose such as glucose, galactose, mannose, allose, and tarose, and examples thereof include pentoses such as ribose.

Since these monomers have their own unique molecular structure, they are important for synthesizing molecular structures such as target-oriented molecular structures or new drug development. 1992 Hirschmann [J. Am. Chem. Soc. 114, 9217-9228, et al. Synthesized bioactive compounds targeting somatostatin receptor and constructed molecular diversity using beta-di-glucoside as a starting material. 2001 Memer [Recent Res.Devel. Organic Chem. 5, 257-278, et al. Synthesized amino sugars using di-mannitol to inhibit inhibitors of various enzymes, such as alpha- or beta-glucosidase, alpha-di-mannose age, and alpha-el-fucosidase. Has been synthesized. On the other hand, Carvalho published a method for synthesizing 2,3,4-trihydroxycyclohexanone using di-glucose in 2004 [Carbohyd. Res. 339, 361-365. The results of these studies vary widely, and in 2002, Grunder [Chem. Rev. 102, 491-514, 1993, Ferrie [Chem. Rev. 93, 2779-2831] summarized the extensive data. This vast research is explained because the structural properties of carbohydrates can produce various isomers. That is, in the case of an asymmetric carbon containing a hydroxyl group in the hexose, it is difficult to selectively react with the hydroxyl group of the desired position by a general chemical method [WO 00/42057]. Some metal catalysts improve selectivity [J. Am. Chem. Soc. 2001, 123, 6496-6502], but efforts to increase selectivity remain a problem.

In order to solve these problems in carbohydrates, the use of enzymatic reactions has recently emerged as an important technology. The enzyme reaction proceeds well at normal temperature and pressure and has an environmentally friendly advantage. In particular, it is very advantageous to use the reaction selectivity of enzymes for the selectivity of protection / deprotection reactions in carbohydrates requiring selectivity. Reaction selectivity in enzymatic reactions is widely studied enantioselectivity used to separate isomers, and regioselectivity is widely used to study selectivity for carbohydrates and multifunctional groups.

Location-selective protection and deprotection methods of existing carbohydrates are disadvantageous because they are often due to the catalytic reaction of heavy metal compounds, the reaction temperature must be low, and the reaction time is long. In addition, it is known that there are disadvantages in environmental aspects such as heavy metal pollution due to the use of a catalyst.

The present invention is to develop a technology for producing pharmaceuticals and fine compounds useful to humans using natural renewable carbohydrates (sugars). In the invention, the use of a biocatalyst will invent an energy-saving and environmentally friendly manufacturing method. Biocatalysts, unlike chemical catalysts, are unique in their reactivity, allowing for the selective synthesis of carbohydrate compounds. Therefore, it is important to establish the production conditions using the biocatalyst, and if necessary, the selected biocatalyst may be used to secure an improved biocatalyst through biochemical or chemical techniques. On the other hand, since biocatalysts show different reaction specificities depending on the molecular structure of the substrate, there is a need for chemical transfer reactions, and thus, a technical invention in which chemical and biochemical methods are fused is required.

Accordingly, the present inventors have studied the position-selective synthesis of such carbohydrate compounds, as a result of the hydrolysis reaction of beta C ₁ ~ C ₆ alkyl tri (C ₁ ~ C ₆ alkanoyl) ribofuranoside with a specific enzyme The present invention has been completed by developing a method for obtaining a compound selectively at a position.

Accordingly, an object of the present invention is to provide a method for preparing ribofuranoside having a hydroxyl group at the carbon position 5.

The present invention is characterized by a method for producing ribofuranoside having a hydroxyl group at the carbon position 5.

Hereinafter, the present invention will be described in more detail as follows.

The present invention is based on the beta C ₁ ~ C ₆ alkyl tri (C ₁ ~ C ₆ alkanoyl) ribofuranoside substrate, and selectively hydrolyzed at the 5 carbon position by a specific enzyme to the hydroxyl group at the 5 carbon position It relates to a method for producing ribofuranoside having.

The molecular structure of the carbohydrate compound is present in the form of pyranoides and furanoids as monosaccharides as follows. Disaccharides also exist in the bound state of these monosaccharides.

In the case of the glucose monomer in the pyranoside form, five hydroxyl groups are present, and it is necessary to selectively react as needed. C1 is an anionic position, and C6 is a primary alcohol, which is different in reactivity from secondary alcohols at other C2 to C4 positions. Therefore, there is a need to selectively react secondary alcohols at the C2 to C4 positions. The same is true of mannose and galactose. In addition, in the case of furanoids, there is a need to selectively react with the same concept.

As shown above, when the substitution at each position is different, each becomes a new compound. Similarly, if each substrate is synthesized with the same acyl donor (Hylsilyl group) will be useful to use the new compound formed by the hydrolysis at different positions through the enzymatic reaction. As the simplest acyljute, an acetyl group is used.

Similar to enzymatic hydrolysis of compounds of the pyranoid family, compounds of the furanoid family can also be selectively hydrolyzed. Representative compounds of furanoids are arabinofuranoids or riboses frequently used in precision compounds. The furanoids used in the present invention are arabinofuranoids which are compounds in the form of di- (D-) or el (L-). Enzymatic hydrolysis results using triacetate compounds of di-furanoarabinose have been reported in the journal by the inventor [Tetrahedron Lett. 2005, 46, pp 607-609. At this time, ERO (Rhizopus oryzae esterase) and PLE (Pig liver esterase) selectively hydrolyzed ester bonds of C2 when various commercialized enzymes were used. In particular, it was observed that the results of selectivity vary depending on the reaction solvent, additives, and reaction temperature when ERO is used. Therefore, it is also important to find the optimal conditions for the enzyme reaction by confirming the reaction selectivity of the substrate among various enzymes and then changing various variables.

In the present invention, beta C ₁ ~ C ₆ alkyl tri (C ₁ ~ C ₆ alkanoyl) ribofuranoside in the carbohydrate as a substrate, Pseudomonas fluorescein-derived lipase (LAK), Berkholderia Sephacia-derived lipase (LAH) ), Pseudomonas Sephacia lipase (PCL), acylase (aspergillus sp.), Pig liver esterase (PLE, pig liver esterase), wheat germ-derived lipase (LWG, Lipase of wheat germ), Bacillus turmoleo Hydrolysis of the hydroxy group at position 5 by selective hydrolysis with an enzyme selected from Bacillus thermoleovarans- derived lipase, thermostable Bacillus-derived lipase, Muco Javanica lipase-derived lipase (Amano lipase M), and alkaline genus-derived lipase It is characterized by a method of producing ribofuranoside having.

As an example of a method for preparing a regioselective compound according to the present invention, the following Scheme 1 is shown.

Scheme 1

In Scheme 1, R is an acetyl group or propionyl group.

As a result of attempting hydrolysis of triacetate of ribofuranoid, which is another furanoside (wherein R is an acetyl group in Scheme 1), PLE (porcine liver), LWG (wheat germ), and Bacillus thermoleovarans ( Bacillus thermoleovarans ) In the lipase derived or thermostable Bacillus-derived lipase it was confirmed that 50% or more of the hydrolysis proceeds selectively at C5.

In particular, the hydrolysis reaction is carried out with a phosphate buffer of pH 7 ~ 7.5 at 10 ~ 35 ℃, the hydrolysis of the triacetate of the ribofuranoid is used together with dimethyl sulfoxide or ethanol as an organic solvent.

Meanwhile, hydrolysis was performed at 10 to 35 ° C. with a phosphate buffer solution having a pH of 7 to 7.5 using propionyl group instead of an acetyl group. As a result, Pseudomonas fluorescens-derived lipase (LAK) and Berkholderia sephasia lipase (LAH) were obtained. ), Pseudomonas Sephacia lipase (PCL), acylase (aspergillus sp.), Pig liver esterase (PLE, pig liver esterase), wheat germ-derived lipase (LWG, Lipase of wheat germ), Bacillus turmoleo It was confirmed that 50% or more of hydrolysis proceeded selectively in C5 from Bacillus thermoleovarans- derived lipase, thermostable Bacillus-derived lipase, Muco Javanicus-derived lipase (Amano lipase M), or alkaline genus-derived lipase.

The present invention relates to the preparation of fine compounds useful to humans using resource-cycle carbohydrates obtained from natural products. At this time, the intermediate for preparing the target compound of the manufacturing method to find the reaction selectivity through the biocatalytic reaction, thereby to build an environment-friendly and energy-saving manufacturing method. In the use of biocatalysts, the general commercialization was focused.

Name and manufacturer of enzyme used in the present invention Enzyme naming Enzyme manufacturers  Pseudomonas fluorescens-derived lipase (LAK), Berkholderia sephasia lipase (LAH), Pseudomonas sephasia lipase (PCL), Acylase (aspergillus sp.), amano Pharmaceutical Co  Muco Jabonicus-derived lipase (Amano lipase M) Porcine liver-derived esterase sigma  Wheat germ-derived lipase (LWG) Fluka  L Bacillus thermoleovarans, L thermostable Bacillus, Genofocus  L Alcaligines sp. (L-10) Chirazyme

Ribofuranoside having a hydroxyl group at the carbon position 5 according to the present invention, the reaction temperature is carried out at room temperature compared to the conventional production method, the selectivity is higher than the chemical method, in terms of low waste discharge It is expected to be very useful for the environment-friendly and energy-saving manufacturing method by having a remarkable effect.

Hereinafter, the present invention will be described in detail with reference to Examples, but the scope of the present invention is not limited to these Examples.

Reference Example 1 Hydrolysis Method A

The substrate (50 mg) was mixed in pH phosphate buffer solution or phosphate buffer solution mixed with organic solvent. An enzyme (mass eq.) Was added thereto and shaken at 30 ° C. at 254 rpm. A portion of the solution was reacted at regular intervals, extracted and dried. The extracted organic layer was dissolved in methanol and analyzed by HPLC.

Reference Example 1 Hydrolysis Method B

Saturated water with 10% acetone in diisopropyl ether. Substrate and enzyme were added to the solution and shaken at 30 ° C. at 254 rpm. This reaction was terminated by removing the enzyme through filtration. A portion of the solution was reacted at regular intervals and analyzed by HPLC.

Example 1: Methyl 2,3,5-triacetyl-beta-di-ribofuranoside (Methyl 2,3,5-Triacetyl-β-D-ribofuranoside)

Commercially available methyl D-ribose was dissolved in pyridine, and acetic anhydride was added thereto and stirred at room temperature for 24 hours. After completion of the reaction, pyridine was removed by distillation under reduced pressure, and extracted with water and ethyl acetate. The organic layer was washed with 5% HCl, water and brine, dried over anhydrous magnesium sulfate, and dried under reduced pressure.

¹ H NMR (CDCl ₃ ,) δ 2.04 (s, 3 H, acetyl), 2.07 (s, 3 H, acetyl), 2.12 (s , 3 H, acetyl), 3.44 (s, 3 H, OCH ₃ ), 3.58-3.73 (m, 1H, H5), 3.75-3.88 (m, 1H, H5 '), 4.19-4.28 (m, 1H, H4), 4.92 (s, 1H, Hl), 5.24 (d , 1 H, H 2, J = 5.4 Hz), 5.37 (dd, 1 H, H 3, J 1 = Jz = 5.4 Hz); ¹³ C NMR (CDCl ₃ ) 20.61 (2 C), 55.78, 62.87, 71.23, 75.24, 82.43, 106.49, 169.68, 170.08 ppm

Example 2 Methyl 2,3-Diacetyl-beta-di-ribofuranoside

As described in Reference Example 1, 2,3,5-triacetyl-beta-di-ribofuranoside, which is a substrate, was subjected to enzymatic reaction to measure the progress of the reaction by thin layer chromatography (TLC), followed by separation. The degree was measured.

¹ H NMR (CDCl ₃ ,) δ 2.07 (s, 3 H, acetyl), 2.12 (s , 3 H, acetyl), 3.44 (s, 3 H, OCH ₃ ), 3.58-3.73 (m, 1 H, H5 ), 3.75-3.88 (m, 1 H, H5 '), 4.19-4.28 (m, 1 H, H4), 4.92 (s, 1 H, Hl), 5.24 (d, 1 H, H2, J = 5.4 Hz ), 5.37 (dd, 1 H, H 3, J 1 = Jz = 5.4 Hz); ¹³ C NMR (CDCl ₃ ) 20.61 (2 C), 55.78, 62.87, 71.23, 75.24, 82.43, 106.49, 169.68, 170.08 ppm

Example 3: Methyl 2,5-Diacetyl-beta-di-ribofuranoside

As described in Reference Example 1, the progress of the reaction was measured by thin layer chromatography (TLC) by enzymatic reaction of 2,3,5-triacetyl-beta-di-ribofuranoside as a substrate, followed by methyl 2,5- Diacetyl-beta-di-ribofuranoside was separated to measure the progress of the reaction.

¹ H NMR (CDCl ₃ ,) δ 2.07 (s, 3 H, acetyl), 2.12 (s , 3 H, acetyl), 3.44 (s, 3 H, OCH ₃ ), 3.58-3.73 (m, 1 H, H5 ), 3.75-3.88 (m, 1 H, H5 '), 4.19-4.28 (m, 1 H, H4), 4.92 (s, 1 H, Hl), 5.24 (d, 1 H, H2, J = 5.4 Hz ), 5.37 (dd, 1 H, H 3, J 1 = Jz = 5.4 Hz); ¹³ C NMR (CDCl ₃ ) 20.61 (2 C), 55.78, 62.87, 71.23, 75.24, 82.43, 106.49, 169.68, 170.08 ppm

Example 4 Methyl 3,5-Diacetyl-beta-di-ribofuranoside

As described in Reference Example 1, the reaction progress was measured by thin layer chromatography (TLC) by enzymatic reaction of 2,3,5-triacetyl-beta-di-ribofuranoside, which is a substrate, and methyl 3,5-. Diacetyl-beta-di-ribofuranoside was separated to measure the progress of the reaction.

¹ H NMR (CDCl ₃ ,) δ 2.07 (s, 3 H, acetyl), 2.12 (s , 3 H, acetyl), 3.44 (s, 3 H, OCH ₃ ), 3.58-3.73 (m, 1 H, H5 ), 3.75-3.88 (m, 1 H, H5 '), 4.19-4.28 (m, 1 H, H4), 4.92 (s, 1 H, Hl), 5.24 (d, 1 H, H2, J = 5.4 Hz ), 5.37 (dd, 1 H, H 3, J 1 = Jz = 5.4 Hz); ¹³ C NMR (CDCl ₃ ) 20.61 (2 C), 55.78, 62.87, 71.23, 75.24, 82.43, 106.49, 169.68, 170.08 ppm

Example 5: Methyl 2,3,5-tripropionyl-beta-di-ribofuranoside (Methyl 2,3,5-tripropionyl β-D-ribofuranoside)

Commercially available methyl D-ribose was dissolved in pyridine, and propionyl anhydride was added thereto and stirred at room temperature for 24 hours. After completion of the reaction, pyridine was removed by distillation under reduced pressure, and extracted with water and ethyl acetate. The organic layer was washed with 5% HCl, water and brine, dried over anhydrous magnesium sulfate, and dried under reduced pressure.

¹ H NMR (CDCl ₃ ) δ 1.11-1.19 (m, 9 H, propionyl-C H ₃ ), 2.31-2.42 (m, 6 H, propionyl-C H _2- ), 3.38 (s, 3 H, OCH ₃ ), 4.13 (dd, 1 H, H5, J = 11.8, 5.3 Hz), 4.28-4.39 (m, 2 H, H4, H5 '), 4.91 (s, 1 H, H1), 5.26 (dd, 1 H , H 2, J = 5.5, 0.7 Hz), 5.34 (dd, 1 H, H 3, J = 6.5, 4.9 Hz); ¹³ C NMR (CDCl ₃ ) δ 8.8, 8.9, 9.0, 27.1, 27.2, 27.3, 55.2, 64.2, 71.4, 74.4, 78.6, 106.2, 173.0, 174.0 ppm

Example 6: Methyl 2,3-dipropionyl-beta-di-ribofuranoside (Methyl 2,3-dipropionyl-β-D-ribofuranoside)

The enzymatic reaction of Method A or B was carried out using the substrate obtained in Example 5 to obtain the reaction product.

¹ H NMR (CDCl ₃ ) δ 1.11-1.19 (m, 6 H, propionyl-C H ₃ ), 2.29-2.43 (m, 4 H, propionyl-C H _2- ), 3.44 (s, 3 H, OCH ₃ ), 3.66 (dd, 1 H, H5, J = 12.1, 4.2 Hz), 3.81 (dd, 1 H, H5 ', J = 12.1, 3.4 Hz), 4.23 (m, 1 H, H4), 4.92 (s , 1 H, H1), 5.27 (dd, 1 H, H2, J = 5.1, 0.8 Hz), 5.38 (t, 1 H, H3, J = 5.7 Hz); ¹³ C NMR (CDCl ₃ ) δ 8.9, 9.0, 27.2, 27.3, 55.7, 62.9, 71.2, 75.1, 77.2, 82.5, 106.6, 173.0, 173.4 ppm

Example 7: Methyl 2,5-dipropionyl-beta-di-ribofuranoside (Methyl 2,5-dipropionyl-β-D-ribofuranoside)

The enzymatic reaction of Method A or B was carried out using the substrate obtained in Example 5 to obtain the reaction product.

¹ H NMR (CDCl ₃ ) δ 1.11-1.19 (m, 6 H, propionyl-C H ₃ ), 2.29-2.43 (m, 4 H, propionyl-C H _2- ), 3.44 (s, 3 H, OCH ₃ ), 3.66 (dd, 1 H, H5, J = 12.1, 4.2 Hz), 3.81 (dd, 1 H, H5 ', J = 12.1, 3.4 Hz), 4.23 (m, 1 H, H4), 4.92 (s , 1 H, H1), 5.27 (dd, 1 H, H2, J = 5.1, 0.8 Hz), 5.38 (t, 1 H, H3, J = 5.7 Hz); ¹³ C NMR (CDCl ₃ ) δ 8.9, 9.0, 27.2, 27.3, 55.7, 62.9, 71.2, 75.1, 77.2, 82.5, 106.6, 173.0, 173.4 ppm

Example 8: Methyl 2,3-dipropionyl-beta-D-ribofuranoside

The enzymatic reaction of Method A or B was carried out using the substrate obtained in Example 5 to obtain the reaction product.

¹ H NMR (CDCl ₃ ) δ 1.11-1.19 (m, 6 H, propionyl-C H ₃ ), 2.29-2.43 (m, 4 H, propionyl-C H _2- ), 3.44 (s, 3 H, OCH ₃ ), 3.66 (dd, 1 H, H5, J = 12.1, 4.2 Hz), 3.81 (dd, 1 H, H5 ', J = 12.1, 3.4 Hz), 4.23 (m, 1 H, H4), 4.92 (s , 1 H, H1), 5.27 (dd, 1 H, H2, J = 5.1, 0.8 Hz), 5.38 (t, 1 H, H3, J = 5.7 Hz); ¹³ C NMR (CDCl ₃ ) δ 8.9, 9.0, 27.2, 27.3, 55.7, 62.9, 71.2, 75.1, 77.2, 82.5, 106.6, 173.0, 173.4 ppm

Example 9

The result of enzymatic reaction by the method of hydrolysis of Reference Example 1 or 2 using methyl 2,3,5-triacetyl-beta-di-ribofuranoside as a substrate by the method synthesized in Example 1 is shown in the following table. 2 is shown.

Example 10

The result of enzymatic reaction by the method of hydrolysis of Reference Example 1 or 2 using methyl 2,3,5-tripropionyl-beta-di-ribofuranoside synthesized in Example 5 as a substrate is shown in Table 2 below. Marked on.

Enzyme (mg) time temperament menstruum Starting material (%) 3-OH (%) 2-OH (%) 5-OH (%) Porcine liver-derived esterase (PLE) 0.5 Beta-methyl triacetyl ribofuranoside DMSO 0.2 2.5 3.6 93 Wheat germ-derived lipase (LWG) 5 Beta-methyl triacetyl ribofuranoside DMSO 5.9 10.5 11.5 72 Wheat germ-derived lipase (LWG) 2.8 Beta-methyl triacetyl ribofuranoside ethanol - 6.1 3.6 84   L Bacillus thermoleovarans 4.5 Beta-methyl triacetyl ribofuranoside DMSO 14.1 4.5 5.1 76.3  L Bacillus thermoleovarans 5 Beta-methyl triacetyl ribofuranoside ethanol 2.9 94.6 L Thermostable bacillus 56 Beta-methyl triacetyl ribofuranoside ethanol 7.2 8.3 5.6 78.9 Acylase 4.5 Beta-methyl tripropionyl ribofuranoside - 34.6 64.4 Pseudomonas fluorescens derived lipase (LAK) 16.5 Beta-methyl tripropionyl ribofuranoside - 7.5 92.5 Pseudomonas Sephacia Derived Lipase (PCL) 74 Beta-methyl tripropionyl ribofuranoside - 3.6 93.5 Berkholderia Sephacia Derived Lipase (LAH) 26 Beta-methyl tripropionyl ribofuranoside - 4.2 91.2 L-10 26 Beta-methyl tripropionyl ribofuranoside - 5.3 90.5  Muco Jabonicus-derived lipase (Amano lipase M) 100 Beta-methyl tripropionyl ribofuranoside - 36.1 2.4 2.5 57.8  L Bacillus thermoleovarans 1.5 Beta-methyl tripropionyl ribofuranoside - 9.1 90.9  L Thermostable bacillus 3 Beta-methyl tripropionyl ribofuranoside - 4.1 91.7

As described above, the method for preparing ribofuranoside having a hydroxyl group at the carbon position 5 according to the present invention has a significant effect in terms of energy-saving and environmental manufacturing methods compared to the conventional manufacturing method, thereby building molecular diversity. It is expected to be very useful for the big effect in the preparation of and fine compounds.

Claims (2)

Beta (C ₁ ~ C ₆ alkyl) -2,3,5-tri (C ₁ ~ C ₆ alkanoyl) ribofuranoside of the following formula 1 as a substrate, Pseudomonas fluorescens-derived lipases, Berkholderia sepacia-derived lipases, Pseudomonas sephasia-derived lipases, asylases ( Aspergillus sp.), Pig liver-derived esterases (PLE, pig liver esterase), wheat germ-derived lipases (LWG) selective hydrolysis at the carbon position 5, enzyme selected from lipase derived from wheat germ lipase, Bacillus thermoleovarans , lipase derived from Muco Javanicus and lipase derived from the genus Alkali genus. A method for producing ribofuranoside having a hydroxy group at the carbon position; [Formula 1]

R ¹ represents a C ₁ to C ₆ alkyl group, and R represents a C ₁ to C ₆ alkanoyl group. The method of claim 1, wherein the substrate is beta methyl 2,3,5-triacetyl ribofuranoside or beta methyl 2,3,5-tripropionyl ribofuranoside.

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