An optically active (3R)- or (3S)-fluorine-containing-3-hydroxybutyric acid ester represented by the formula: ##STR1## wherein R represents an alkyl group of C.sub.3 -C.sub.16 and A represents CF.sub.3, CHF.sub.2 or CH.sub.2 F, which is useful for synthesis of optically active substances, is prepared with high optical purity by ester exchange reaction between an alcohol represented by the formula: ROH wherein R is as defined above and optically active (3R)- or (3S)-fluorine-containing-3-hydroxybutyric acid ethyl ester of ##STR2## in the presence of an ammonium salt of sulfonic acid.
一种具有光学活性的(3R)或(3S)-含
氟-3-羟基
丁酸酯,其
化学式为:##STR1## 其中R表示C.sub.3-C.sub.16的烷基,A表示CF.sub.3、CHF.sub.2或CH.sub.2F。该酯可用于合成光学活性物质,并通过在
磺酸铵盐存在下,使ROH(其中R如上所定义)和(3R)或(3S)-含
氟-
3-羟基丁酸乙酯##STR2##之间进行酯交换反应,高光学纯度地制备。