PROCESS FOR PRODUCING OPTICALLY ACTIVE CYANOHYDRINS

摘要

An optically active cyanohydrin represented by the following general formula (1): wherein each of R1 and R2 is a hydrogen atom or an amino- protecting group, and the configurations relating to the carbon atoms at the *2-position and *3-position are as follows: in the case of the carbon atom at the *2-position being in R-configuration, the carbon atom at the *3- position is in S-configuration, and in the case of the carbon atom at the *2-position being in S-configuration, the carbon atom at the *3-position is in R-configuration, can be efficiently produced by crystallizing one of the optically active cyanohydrins while treating a mixture of cyanohydrin diastereomers in the presence of an amine and an organic solvent to change the configuration relating to the carbon atom at the 2-position and thereby cause isomerization.