ethyl 3-hydroxy-2-methylbutanoate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The recombinant E. coil HB101(pNTS1G) obtained in Example 10 was inoculated in 100 ml of a 2×YT medium sterilized in a 500 ml Sakaguchi flask, and cultured with agitation at 37° C. for 13 hours. Glucose, 7.5 g, 3.2 mg of NADP, and then 4 g of ethyl 2-methyl-3-oxoacetate were added to 50 ml of the resultant culture. The culture was stirred at 30° C. while being adjusted at pH 6.5 with a 5 M sodium hydroxide solution to allow for reaction for 18 hours. After the reaction, the reaction solution was subjected to extraction using ethyl acetate, the solvent was removed under decompression, and the concentrate was purified by silica gel column chromatography, to obtain 3.5 g of ethyl 3-hydroxy-2-methylbutyrate. The optical purity of the ethyl 3-hydroxy-2-methylbutyrate was analyzed as follows and found to be 91.6% e.e. The analysis was performed in the following manner. The sample was reacted with sodium cyanide in demethyl sulfoxide at room temperature to obtain ethyl 4-cyano-3-hydroxybutyrate, which was then changed to a benzoic ester using benzoyl chloride under the presence of pyridine. The optical purity of the benzoic ester was measured by the HPLC method. 1H-NMR(CDC13)δ(ppm): 1.17(3H,t), 1.22(2H,t), 1.28(3H,t), 2.46(1H,m), 2.82(1H,br), 3.90(1H,m), 4.18(2H,q).

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 0.01 Mole of ethyl 2-methyl-3-fluorenoyloxybutyrate was prepared from 0.04 mol of ethyl 2-methyl-3-hydroxybutyrate and 0.05 mol of fluorenoyl chloride (9-fluorenyl carbonyl chloride) following the procedure as described in step 3) of the Preparation Example 3. Yield 25%. of the Preparation Example 3

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Ethyl 2-methyl-3-hydroxybutyrate was prepared following the procedure as described in step 1) of Preparation Example 2, except for that ethyl 2-methyl-3-oxo-butyrate was used to replace for ethyl acetoacetate. Yield 60%. of Preparation Example 2

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 6 L Erlenmeyer flask containing Baker's yeast (100 g) and sucrose (150 g) was added tap water (1000 mL) and the reaction mixture was mechanically stirred at room temperature for 0.5 h. Ethyl 2-methylacetoacetate (10 g, 0.0694 mol) was added to the reaction mixture and stirring continued for 24 h. Sucrose (50 g) was added and stirring continued for another 24 h. Hyflo super cel (50 g) was added to the reaction mixture and filtered through a sintered glass funnel. The aqueous solution was then extracted with ether (1.5 L), dried over sodium sulfate, and filtered. The solvent ether was removed via simple distillation to obtain ethyl 3-hydroxy-2-methylbutyrate (10 g, 100%) as a mixture of two isomers: 1H NMR (CDCl3) δ 1.18-1.30 (18H, m), 2.47-2.52 (2H, m), 3.85-3.91 (1H, m), 4.05-4.10 (1H, m), 4.13-4.21 (4H, m). stirring continued for 24 h stirring continued for another 24 h Hyflo super cel (50 g) was added to the reaction mixture filtered through a sintered glass funnel The aqueous solution was then extracted with ether (1.5 L) dried over sodium sulfate filtered The solvent ether was removed via simple distillation

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The recombinant E. coil HB101(pNTS1G) obtained in Example 10 was inoculated in 100 ml of a 2×YT medium sterilized in a 500 ml Sakaguchi flask, and cultured with agitation at 37° C. for 13 hours. Glucose, 7.5 g, 3.2 mg of NADP, and then 4 g of ethyl 2-methyl-3-oxoacetate were added to 50 ml of the resultant culture. The culture was stirred at 30° C. while being adjusted at pH 6.5 with a 5 M sodium hydroxide solution to allow for reaction for 18 hours. After the reaction, the reaction solution was subjected to extraction using ethyl acetate, the solvent was removed under decompression, and the concentrate was purified by silica gel column chromatography, to obtain 3.5 g of ethyl 3-hydroxy-2-methylbutyrate. The optical purity of the ethyl 3-hydroxy-2-methylbutyrate was analyzed as follows and found to be 91.6% e.e. The analysis was performed in the following manner. The sample was reacted with sodium cyanide in demethyl sulfoxide at room temperature to obtain ethyl 4-cyano-3-hydroxybutyrate, which was then changed to a benzoic ester using benzoyl chloride under the presence of pyridine. The optical purity of the benzoic ester was measured by the HPLC method. 1H-NMR(CDC13)δ(ppm): 1.17(3H,t), 1.22(2H,t), 1.28(3H,t), 2.46(1H,m), 2.82(1H,br), 3.90(1H,m), 4.18(2H,q).

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The recombinant E. coil HB101(pNTS1G) obtained in Example 10 was inoculated in 100 ml of a 2×YT medium sterilized in a 500 ml Sakaguchi flask, and cultured with agitation at 37° C. for 13 hours. Glucose, 7.5 g, 3.2 mg of NADP, and then 4 g of ethyl 2-methyl-3-oxoacetate were added to 50 ml of the resultant culture. The culture was stirred at 30° C. while being adjusted at pH 6.5 with a 5 M sodium hydroxide solution to allow for reaction for 18 hours. After the reaction, the reaction solution was subjected to extraction using ethyl acetate, the solvent was removed under decompression, and the concentrate was purified by silica gel column chromatography, to obtain 3.5 g of ethyl 3-hydroxy-2-methylbutyrate. The optical purity of the ethyl 3-hydroxy-2-methylbutyrate was analyzed as follows and found to be 91.6% e.e. The analysis was performed in the following manner. The sample was reacted with sodium cyanide in demethyl sulfoxide at room temperature to obtain ethyl 4-cyano-3-hydroxybutyrate, which was then changed to a benzoic ester using benzoyl chloride under the presence of pyridine. The optical purity of the benzoic ester was measured by the HPLC method. 1H-NMR(CDC13)δ(ppm): 1.17(3H,t), 1.22(2H,t), 1.28(3H,t), 2.46(1H,m), 2.82(1H,br), 3.90(1H,m), 4.18(2H,q).

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 6 L Erlenmeyer flask containing Baker's yeast (100 g) and sucrose (150 g) was added tap water (1000 mL) and the reaction mixture was mechanically stirred at room temperature for 0.5 h. Ethyl 2-methylacetoacetate (10 g, 0.0694 mol) was added to the reaction mixture and stirring continued for 24 h. Sucrose (50 g) was added and stirring continued for another 24 h. Hyflo super cel (50 g) was added to the reaction mixture and filtered through a sintered glass funnel. The aqueous solution was then extracted with ether (1.5 L), dried over sodium sulfate, and filtered. The solvent ether was removed via simple distillation to obtain ethyl 3-hydroxy-2-methylbutyrate (10 g, 100%) as a mixture of two isomers: 1H NMR (CDCl3) δ1.18-1.30 (18H, m), 2.47-2.52 (2H, m), 3.85-3.91 (1H, m), 4.05-4.10 (1H, m), 4.13-4.21 (4H, m). stirring continued for 24 h stirring continued for another 24 h Hyflo super cel (50 g) was added to the reaction mixture filtered through a sintered glass funnel The aqueous solution was then extracted with ether (1.5 L) dried over sodium sulfate filtered The solvent ether was removed via simple distillation

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a 6 L Erlenmeyer flask containing Baker's yeast (100 g) and sucrose (150 g) was added tap water (1000 mL) and the reaction mixture was mechanically stirred at room temperature for 0.5 h. Ethyl 2-methylacetoacetate (10 g, 0.0694 mol) was added to the reaction mixture and stirring continued for 24 h. Sucrose (50 g) was added and stirring continued for another 24 h. Hyflo super cel (50 g) was added to the reaction mixture and filtered through a sintered glass funnel. The aqueous solution was then extracted with ether (1.5 L), dried over sodium sulfate, and filtered. The solvent ether was removed via simple distillation to obtain ethyl 3-hydroxy-2-methylbutyrate (10 g, 100%) as a mixture of two isomers: 1H NMR (CDCl3) δ1.18-1.30 (18H, m), 2.47-2.52 (2H, m), 3.85-3.91 (1H, m), 4.05-4.10 (1H, m), 4.13-4.21 (4H, m). stirring continued for 24 h stirring continued for another 24 h Hyflo super cel (50 g) was added to the reaction mixture filtered through a sintered glass funnel The aqueous solution was then extracted with ether (1.5 L) dried over sodium sulfate filtered The solvent ether was removed via simple distillation

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The recombinant E. coli HB101 (pNTS1G) obtained in Example 10 was inoculated in 100 ml of a 2×YT medium sterilized in a 500 ml Sakaguchi flask, and cultured with agitation at 37° C. for 13 hours. Glucose, 7.5 g, 3.2 mg of NADP, and then 4 g of ethyl 2-methyl-3-oxoacetate were added to 50 ml of the resultant culture. The culture was stirred at 30° C. while being adjusted at pH 6.5 with a 5 M sodium hydroxide solution to allow for reaction for 18 hours. After the reaction, the reaction solution was subjected to extraction using ethyl acetate, the solvent was removed under decompression, and the concentrate was purified by silica gel column chromatography, to obtain 3.5 g of ethyl 3-hydroxy-2-methylbutyrate. The optical purity of the ethyl 3-hydroxy-2-methylbutyrate was analyzed as follows and found to be 91.6% e.e. The analysis was performed in the following manner. The sample was reacted with sodium cyanide in demethyl sulfoxide at room temperature to obtain ethyl 4-cyano-3-hydroxybutyrate, which was then changed to a benzoic ester using benzoyl chloride under the presence of pyridine. The optical purity of the benzoic ester was measured by the HPLC method. 1H-NMR(CDCl3) δ (ppm): 1.17(3H,t), 1.22(2H,t), 1.28(3H,t), 2.46(1H,m), 2.82(1H,br), 3.90(1H,m), 4.18(2H,q).

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 0.01 Mole of ethyl 2-methyl-3-fluorenoyloxybutyrate was prepared from 0.04 mol of ethyl 2-methyl-3-hydroxybutyrate and 0.05 mol of fluorenoyl chloride (9-fluorenyl carbonyl chloride) following the procedure as described in step 3) of the Preparation Example 3. Yield 25%. of the Preparation Example 3