Method for the production of (r)- and (S)-8-chloro-6-hydroxyoctanic acid alkyl esters by enzymatic reduction

摘要

The invention relates to a method for the production of (R)- or (S)-8-chloro-6-hydroxyoctanoic acid alkyl esters of the general formula (R)-II or (S)-II in which R has the meaning C_1-4-alkyl, from 8-chloro-6-oxooctanoic acid alkyl esters of the general formula I in which R has the above meaning, by enzymatic reduction using alcohol dehydrogenases, such as Lactobacillus brevis or Thermoanaerobium brokii, in the presence of cofactor regeneration systems. The resulting (R)- and (S)-8-chloro-6-hydroxyoctanoic acid esters can be converted in a known manner into (R)-alpha-lipoic acid and (S)-alpha-lipoic acid, respectively.