Aluminium-chloride-promoted reactions of ethyl acrylate with olefins

Abstract

Contrary to an earlier report,¹ the aluminium-chloride-promoted reaction of ethyl acrylate with olefins does not afford cyclobutane derivatives. In benzene, ethyl acrylate reacts with isobutylene or 2,3-dimethylbut- 2-ene to afford the terminally unsaturated products (5) and (9) respectively. In 1,2-dichloroethane-nitromethane the initial products undergo isomerization or rearrangement. Un-ambiguous routes to 2,2- dimethylcyclobutanecarboxylic acid (19) and (2,2,3,3- tetramethylcyclobutyl)- methanol (26) are described.