| 摘要 |
PURPOSE:To produce L-lactic acid from a reaction mixture of D-lactic acid and unreacted D-2-chloropropionic acid, by heating the mixture under specific condition, thereby reacting only the propionic acid with water while keeping the D-lactic acid in the mixture from the influence of heat. CONSTITUTION:DL-2-Chloropropionic acid or its alkali metal salt or alkaline earth metal salt is made to react with water in the presence of a dehalogenation enzyme (e.g. haloacid dehalogenase) reacting specifically and exclusively to the L-isomer of DL-2-chloropropionic acid, and the unreacted alkali metal salt or alkaline earth metal salt of D-2-chloropropionic acid containing the resultant D-lactic acid or its alkali metal salt or alkaline earth metal salt is heated in the presence of water at 40-120 deg.C, preferably 60-110 deg.C to obtain D-lactic acid. EFFECT:Simple operation. It is not necessary to separate D-lactic acid from D-2-chloropropionic acid. |
