Optically active ethyl(S)-4-chloro-3-hydrobutanoate((S)-CHBE),a useful chiral synthon,was prepared by stereoselective bioreduction of ethyl 4chloro-3-oxobutanoate(COBE) with Candida magnoliae cells.

• 利用木兰假丝酵母催化的4-氯乙酰乙酸乙酯(COBE)立体选择性还原反应；制备了具有光学活性的手性化合物(S)-4-氯-3-羟基丁酸乙酯((S)-CHBE).