发明名称 |
Process for the preparation of substituted carboxylic esters |
摘要 |
A process for the preparation of 2(S)-alkyl-5-halogenpent-4-ene carboxylic esters by enzymatic hydrolysis, comprising the steps: a) enzymatic hydrolysis of racemic 2-alkyl-5-halogenpent-4-ene carboxylic esters in aqueous and alkaline medium in the presence of an esterase; b) isolation of 2(S)alkyl-5-halogenpent-4-ene carboxylic esters by extraction with an organic solvent; c) isolation of 2(R)-alkyl-5-halogenpent-4-ene carboxylic acids from the aqueous-alkaline medium; d) Esterification of 2(R)-alkyl-5-halogenpent-4-ene carboxylic acids, e) subsequent racemization to form 2-alkyl-5-halogenpent-4-ene carboxylic esters; and f) return of the racemate obtained in step e) to step a), if necessary together with fresh racemic 2-alkyl-5-halogenpent-4-ene carboxylic esters. The process permits the undesired R-stereoisomers to be converted into the desired 2(S)-alkyl-5-halogenpent-4-ene carboxylic esters to avoid waste product from the synthesis.
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申请公布号 |
US2004132148(A1) |
申请公布日期 |
2004.07.08 |
申请号 |
US20030477739 |
申请日期 |
2003.11.14 |
申请人 |
HEROLD PETER;STUTZ STEFAN |
发明人 |
HEROLD PETER;STUTZ STEFAN |
分类号 |
C12P7/62;C12P41/00;(IPC1-7):C12P7/62;C12P7/40 |
主分类号 |
C12P7/62 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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