Regiospecific Methylation of Cyclopentenone Derivatives

Abstract

In connection with our continuing interest in cyclopentenone chemistry,¹ we record here our observations concerning the regiospecific methylation of six simple cyclopentenones. Although several recent reports² have demonstrated the feasibility of alkylating either the kinetically or thermodynamically derived dienolate of cyclohexenone systems, similar reports on the alkylation of cyclopentenone derivatives have remained obscure.³ This is presumably due, in the case of equilibrium alkylation, to the availability of alternative pathways (self-condensation) which compete efficiently with alkylation.