Synthesis of (±)-kainic acid by dearomatising cyclisation of a lithiated N-benzyl p-anisamide

Abstract

N-Benzyl p-anisamide 6, on lithiation with ButLi in the presence of HMPA, undergoes a stereoselective anionic cyclisation with loss of aromaticity to give a bicyclic enone which may be converted in nine steps to (±)-kainic acid.