In the presence of a metal catalyst such as a samarium compound, an enol ester compound shown by the formula (1) is reacted with a carbonyl compound shown by the formula (3) and a cyanogenation agent to produce an .alpha.-cyanohydrin ester shown by the formula (4): ##STR1## wherein R.sup.1, R.sup.7, and R.sup.8 are the same or different from each other, each representing a non-reactive atom or a non-reactive organic group; R.sup.2, R.sup.3, and R.sup.4 are the same or different from each other, each representing a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. By hydrolyzing the obtained compound, the corresponding .alpha.-hydroxy acid or a salt thereof can be obtained. According to the above processes, an .alpha.-cyanohydrin ester and an .alpha.-hydroxy acid can be obtained in high yields.
在
金属催化剂的存在下,如
钐化合物,通过以下公式(1)所示的烯醇酯化合物与以下公式(3)所示的羰基化合物和
氰化剂反应,产生以下公式(4)所示的α-
氰醇酯:其中R.sup.1、R.sup.7和R.sup.8相同或不同,每个代表非反应性原子或非反应性有机基团;R.sup.2、R.sup.3和R.sup.4相同或不同,每个代表一个氢原子或具有1至5个碳原子的烷基基团。通过
水解所得化合物,可以获得相应的α-羟基酸或其盐。根据上述过程,可以高产率地获得α-
氰醇酯和α-羟基酸。