摘要
考察了面包酵母发酵液直接催化4-氯-乙酰乙酸乙酯（COBE）的不对称还原反应,并进行了手性添加物的筛选和反应条件的优化实验. 结果表明,以β-环糊精为手性添加物时,酵母发酵液催化COBE不对称还原生成光活性产物（S）-4-氯-3-羟基-丁酸乙酯（（S）-CHBE）的产率和ee值分别高达76%和92%. 在一定条件下,增大β-环糊精浓度,有利于（S）-CHBE的生成. 最佳酵母菌培养时间为16～18 h, 最佳反应温度和pH值分别为29～31 ℃和7.2.
The asymmetric reduction of ethyl. 4-chloro-3-oxobutanoate （COBE） to optically active ethyl 4-chloro- 3-hydroxybutanoate （CHBE） directly catalyzed by yeast fermentation broth and the influence of chiral additives and reaction conditions on this reaction were studied. The concentrations of COBE and （S） CHBE, and the optical purity of the product were determined by gas chromatography and high-performance liquid chromatography with a Chiralcel OB column, respectively. In the yeast fermentation broth without any chiral additive, the substrate was decomposed and the pH value of the reaction mixture decreased sharply. When β-cyclodextrin was used as the chiral additive, the yield and enantiomeric excess of （S）-CHBE reached as high as 76 % and 92 %, respectively. Under specified conditions, high β-cyclodextrin concentration favored （S）-CHBE formation. The optimum reaction conditions are 29-31 ℃ , pH 7.2, and yeast cultivation time of 16-18 h.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2006年第4期314-318,共5页
