Aluminum Chloride-Mediated Acylation of Methylenecyclobutanes. A Facile Synthetic Protocol for the Construction of Substituted Cyclopentenes

Reactions of methylenecyclobutanes (MCBs) with acyl chlorides produce the corresponding substituted cyclopentene derivatives in moderate to high yields via ring enlargement in the presence of aluminum chloride under mild conditions. A plausible mechanism has been proposed on the basis of control and deuterium labeling experiments.