METHOD FOR THE PREPARATION OF CIS-ALKENYL BROMIDE AND ACETATE

摘要

A novel and improved synthetic route for the preparation of several kinds of cis-alkenyl acetates of the formula RCH=CHCH2CH2(CH2)nOCOCH3, in which R is an alkyl group having from 1 to 8 carbon atoms and n is a positive integer from 1 to 10, which compounds are known as sexual pheromone compounds of various noxious insects utilizable as a powerful means for the extermination of the insects, is proposed. The inventive method comprises cross coupling reaction of a Grignard reagent of a cis-alken-3-yl chloride of the formula RCH=CHCH2CH2Cl with an alpha , omega -dibromoalkane of the formula Br(CH2)nBr to form a cis-alkenyl bromide of the formula RCH=CHCH2(CH2)nBr which is further reacted with an alkali metal acetate.