Preparation of 3-(arylvinyl)-2,2-dimethyl-cyclopropane-1-carboxylic acid esters and new intermediate therefor

摘要

A process for the preparation of a 3-(arylvinyl)-2,2-dimethyl-cyclopropane-1-carboxylic acid ester of the formula <IMAGE> in which Ar is an aromatic radical, R is alkyl or an alcohol radical customary in pyrethroids, and R1 is hydrogen, fluorine or chlorine, comprising reacting a compound of the formula <IMAGE> <IMAGE> <IMAGE> with respectively, one, two or three equivalents of a base at a temperature between about -20 DEG and +60 DEG C. The compounds are insecticidally active. Numerous syntheses of the starting materials, some involving new intermediates, are also shown.