反应详情

Suspend trans-cyclopropane-1,2-dicarboxylic acid dimethylester (59.8 g, 0.378 mol) is suspended in 1.0N phosphate buffer (1.5 L, pH=7) add pig liver esterase (2.25 mL, 7500 units), and monitor NaOH consumption with a pH meter to control the reaction. After 3 h the consumption of 189 mL of 2N NaOH indicates the complete hydrolysis of the diester to the monomethylester. Acidified the clear solution by the addition of SN HCl to a pH=1. Separate the enzyme by addition of dichloromethane (500 mL) and diatomaceous earth (25 g). Stir for 5 min, and then filter the mixture. Saturate the filtrate with NaCl, and extract with ethyl acetate (5 times). Combine the extracts, dry (Na2SO4) and evaporate to obtain 50.8 g (93%) of solid, mp 46-47° C., m/z=45 (M+H)+

1. additionadd pig liver esterase (2.25 mL, 7500 units)
2. customNaOH consumption with a pH meter
3. customthe reaction
4. customAfter 3 h the consumption of 189 mL of 2N NaOH
5. customthe complete hydrolysis of the diester to the monomethylester
6. customSeparate the enzyme
7. additionby addition of dichloromethane (500 mL) and diatomaceous earth (25 g)
8. filtrationfilter the mixture
9. concentrationSaturate the filtrate with NaCl
10. extractionextract with ethyl acetate (5 times)
11. dry with materialCombine the extracts, dry (Na2SO4)
12. customevaporate