Method of converting an ester of an optically active cyclopropanec acid and an optically active alcohol of the structure (R) into an ester of the chiral acid of the optically active alcohol of the structure (S), (S)--Cyano-3-phenoxybenzyl-2,2-dimethyl-3R-(2, 2-dichlorvinyl)-cyclopropan-1R-carboxylate and its insecticides

摘要

A process for the preparation of an ester of chiral (A) acid with an optically active (S) alpha -cyano-3-phenoxybenzyl alcohol by reacting an ester of chiral (A) acid with alpha -cyano-3-phenoxybenzyl alcohol of the formula IMAGE B in its optically active (R) form or a racemic (R,S) mixture or a mixture of esters of said (R) alcohol and (S) alcohol in non-equimolecular proportions designated herein as "ester (R+S)" with a base selected from the group consisting of ammonium hydroxide, primary, secondary and tertiary amines, quaternary ammonium compounds, liquid amines of high molecular weight, ion exchange resins of a basic character and a catalytic amount of a strong base in at least one solvent in which the ester of the (R) alcohol is soluble and in which the ester of the (S) alcohol is insoluble and recovering from the resulting medium the chiral (A) acid ester of the (S) alcohol which is insoluble.