METHOD FOR THE RACEMIZATION OF (2)-2-(4- DIFLUOROMETHOXYPHENYL)-3-METHYLBUTYRIC ACID

摘要

A METHOD FOR THE RACEMIZATION OF (2)-2- (4-DIFLUOROMETHOXYPHENYL)-3-METHYLBUTYRIC ACID A method for the racemization and hydrolysis of alkyl esters of (-)-2-(4-difluoromethoxyphenyl)-3-methylbutyric acid, followed by the resolution of said resulting racemic acid into its optically active components via salts prepared from the same with optically active amines and recovery of the dextrorotatory (+) isomer therefrom. The present invention also relates to insecticidal pyrethroids prepared from (+)-2-(4-di-fluoromethoxyphenyl)-3-methylbutyric acid.