(3aS,6aR)-1,3a,4,5,6,6a-hexahydrocyclopenta[c]furan-3-one

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: (1R,5S)-(+)-7-oxabicyclo[3.3.0]octan-6-one (1 gram) was dissolved in 5 ml of absolute ethanol, followed by the addition of 0.5 gram of gaseous ammonia. The solution was kept in a stoppered flask, and the progress of the reaction was followed by thin layer chromatography (eluent dichloromethane/methanol 20:1). After the reaction was judged complete, the ethanol was evaporated and the resulting residue redissolved in ethyl acetate. Ammonia was removed by extraction with 1% HCl, and the ethyl acetate solution was dried over MgSO4, filtered, and rotary evaporated to leave 0.7 grams of (1S,2R)-2-hydroxymethyl-1-cyclopentanecarboxamide. The solution was kept in a stoppered flask the ethanol was evaporated the resulting residue redissolved in ethyl acetate Ammonia was removed by extraction with 1% HCl the ethyl acetate solution was dried over MgSO4 filtered rotary evaporated

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Glycine (18.8 grams) is dissolved in 2 liters of deionized water, and the pH is adjusted by the addition of 10% sodium hydroxide to 9.0. Cis-1,2-cyclopentane dimethanol (10.0 grams) is added to the glycine solution with stirring until dissolution occurs, followed by the addition of β-NAD+ (Sigma, 2 grams) and flavin mononucleotide (Sigma, 30 grams). To the resulting clear orange solution is added horse liver alcohol dehydrogenase (Sigma, 250 mg, approximately 400 units). After the enzyme has dissolved the pH is readjusted to 9.0 with 10% sodium hydroxide, and the reaction mixture is stirred at 30° C. During the reaction, the pH is maintained at 9.0 with a pH-stat by the addition of 10% sodium hydroxide. Progress of the reaction is monitored by thin layer chromatography (Silica gel plates, eluent 1:1 ethyl acetate-methylene chloride; visualization by dipping in a solution of 5% anisaldehyde in ethanol and heating). When the reaction is complete as judged by thin layer chromatography, the reaction mixture is adjusted to a pH of 13 with 10 M sodium hydroxide and then extracted 3 times with 250 ml of methylene chloride. The pH of the aqueous mixture is then adjusted to 3 with concentrated HCl, followed by continuous extraction with 1 liter of ethyl acetate for 24 hours. The ethyl acetate extract is dried over anhydrous magnesium sulfate and evaporated under reduced pressure to yield (1R,5S)-(+)-7-oxabicyclo[3.3.0]octan-6-one (9 grams) as an orange oil. The product may be further purified by distillation at reduced pressure to yield a colorless oil. After the enzyme has dissolved the pH the reaction mixture is stirred at 30° C During the reaction heating) extracted 3 times with 250 ml of methylene chloride followed by continuous extraction with 1 liter of ethyl acetate for 24 hours The ethyl acetate extract is dried over anhydrous magnesium sulfate evaporated under reduced pressure

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: (1R,5S)-(+)-7-oxabicyclo[3.3.0]octan-6-one (1 gram) was dissolved in 5 ml of absolute ethanol, followed by the addition of 0.5 gram of gaseous ammonia. The solution was kept in a stoppered flask, and the progress of the reaction was followed by thin layer chromatography (eluent dichloromethane/methanol 20:1). After the reaction was judged complete, the ethanol was evaporated and the resulting residue redissolved in ethyl acetate. Ammonia was removed by extraction with 1% HCl, and the ethyl acetate solution was dried over MgSO4, filtered, and rotary evaporated to leave 0.7 grams of (1S,2R)-2-hydroxymethyl-1-cydopentanecarboxamide. The solution was kept in a stoppered flask the ethanol was evaporated the resulting residue redissolved in ethyl acetate Ammonia was removed by extraction with 1% HCl the ethyl acetate solution was dried over MgSO4 filtered rotary evaporated

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Glycine (18.8 grams) is dissolved in 2 liters of deionized water, and the pH is adjusted by the addition of 10% sodium hydroxide to 9.0. Cis-1,2-cydopentane dimethanol (10.0 grams) is added to the glycine solution with stirring until dissolution occurs, followed by the addition of β-NAD+ (Sigma, 2 grams) and flavin mononucleotide (Sigma, 30 grams). To the resulting dear orange solution is added horse liver alcohol dehydrogenase (Sigma, 250 mg, approximately 400 units). After the enzyme has dissolved the pH is readjusted to 9.0 with 10% sodium hydroxide, and the reaction mixture is stirred at 30° C. During the reaction, the pH is maintained at 9.0 with a pH-stat by the addition of 10% sodium hydroxide. Progress of the reaction is monitored by thin layer chromatography (Silica gel plates, eluent 1:1 ethyl acetate-methylene chloride; visualization by dipping in a solution of 5% anisaldehyde in ethanol and heating). When the reaction is complete as judged by thin layer chromatography, the reaction mixture is adjusted to a pH of 13 with 10 M sodium hydroxide and then extracted 3 times with 250 ml of methylene chloride. The pH of the aqueous mixture is then adjusted to 3 with concentrated HCl, followed by continuous extraction with 1 liter of ethyl acetate for 24 hours. The ethyl acetate extract is dried over anhydrous magnesium sulfate and evaporated under reduced pressure to yield (1R,5S)-(+)-7-oxabicyclo[3.3.0]octan-6-one (9 grams) as an orange oil. The product may be further purified by distillation at reduced pressure to yield a colorless oil. After the enzyme has dissolved the pH the reaction mixture is stirred at 30° C During the reaction heating) extracted 3 times with 250 ml of methylene chloride followed by continuous extraction with 1 liter of ethyl acetate for 24 hours The ethyl acetate extract is dried over anhydrous magnesium sulfate evaporated under reduced pressure