PROCESS FOR PRODUCING TRANS-2,2-DIMETHYL-3-(2,2-DICHLORO-VINYL)-CYCLOPROPANE-CARBOXYLIC ACID

摘要

There is provided a novel process for the preparation of trans-2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropanecarboxylic acid (=trans-permethric acid) of the formula I …… which is characterised in that chloroketones of the formula (II) …… in which… Z represents chlorine or bromine… are reacted with an aqueous solution of alkali metal hydroxide (preferably sodium hydroxide or potassium hydroxide). …trans-Permethric acid is a valuable intermediate in the preparation of pyrethroids.