PROCESSES FOR THE PREPARATION OF OPTICALLY ACTIVE CYANOMETHYL ESTERS OF ALPHA-CHIRAL CARBOXYLIC ACIDS AND OPTIONALLY SUBSTITUTED S-ALPHA-CYANO-3-PHENOXYBENZYL ALCOHOL

摘要

Stereoisomerically-enriched cyanomethyl esters are prepared by treating a non-symmetrical ketene or an alphachiral carboxylic acid halide or reactive derivative thereof with an optically-active alphahydroxynitrile. Certain optically-active optionally substituted S-alphacyano-3-phenoxy-benzyl alcohol intermediates are prepared by treating the corresponding aldehyde of ketone with a source of hydrogen cyanide in the presence of a substantially water-immiscible, aprotic solvent and a cyclo(D-phenylalanyl-D-histidine) as a catalyst.