A METHOD FOR EPIMERIZING AN OPTICALLY ACTIVE BENZYLALCOHOL DERIVATIVE

摘要

A method for epimerizing an optically active benzylalcohol derivative of the formula: CHEM wherein ZO is a protected or unprotected hydroxy group, is disclosed. Said epimerization can be conducted by the steps of: (a) condensing said optically active benzylalcohol derivative (I) or a salt thereof with a caboxylic acid compound of the formula: R1COOH (II) wherein R1CO is an acyl group, or a reactive derivative thereof to give an optically active N-acylbenzylalcohol derivative of the formula: CHEM wherein R1CO and ZO are the same as defined above; (b) subjecting the optically active N-acylbenzylalcohol derivative (III) to intramolecular cyclization in the presence of a thionyl halide; and (c) treating the product with an alkali agent. )