面包酵母催化不对称合成4-氯-(R)-3-羟基丁酸乙酯

Asymmetric synthesis of ethyl 4-Chloro-(R)-3-hydroxybutyrate with baker′s yeast

以4 氯乙酰乙酸乙酯为原料,以面包酵母为手性生物催化剂,选择性合成光学活性4 氯 (R) 3 羟基丁酸乙酯。经IR、GC MS、1HNMR和旋光度测定,表明所得产品的结构与预期的结构一致。分别考察了面包酵母用量、葡萄糖浓度、底物投入量、pH值、反应时间以及反应温度等因素对产品比旋光度的影响。结果表明,4 氯乙酰乙酸乙酯不对称生物还原反应的适宜条件为:面包酵母6 0 0g/L、葡萄糖2 0g/L、反应温度34℃、底物加量16mL/L、反应时间4 8h、pH为5 ,产品的比旋光度为[α]2 0D =+13 9°。

Optical active ethyl 4-cloro-（ R）-3-hydroxybutyrate was prepared by stereo selective bioreduction of ethyl 4-chloro-acetoacetate with baker＇s yeast. Its structure was elucidated by IR, GC-MS and ^1HNMR. The factors influencing the synthesis were investigated. The results showed that the optimal reaction condition as follows：baker＇s yeast 600 g/L, mass concentration of glucose 20 g/L, feeding rate of substrate 16 mL/L, pH 5, reaction time 48 h, temperature 34 ℃. The specific rotation of the product was [α]^20D= ＋ 13.9°.