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.