PROCESS FOR THE PREPARATION OF OPTICALLY-ACTIVE CYANOMETHYL ESTERS

摘要

A S- α -cyano-3-phenoxybenzyl alcohol deriv. is prepd. by treating 3- phenoxybenzaldehyde with a source of HCN in the presence of a water- immiscible aprotic solvent and a cyclo-(D-phenylalanyl-D-histidine) dipeptide catalyst. An optically active cyanomethyl ester of (I) [R1=R2=R3=R4=substitute is prepd. by reacting α-chiral (optically active) carboxylic acid halide or its reactive deriv. with optically active S-α-cyano-3-phenoxybenzyl alcohol. A cpd. of formula (I) is also prepd. by reacting a non-symmetrical ketene with an α- hydroxynitrile or with an aldehyde or ketone and a source of cyanide ions in the presence of tertiary amine catalyst. (I) is obtained in a high yield by a direct synthesis.