A Convenient Synthesis of Methyl 4-Substituted Benzoates via Diels-Alder Reaction in the Presence of Palladium on Activated Carbon

Abstract

The thermal reaction of methyl 2-oxo-2H-pyran-5-carboxylates with substituted styrenes in the presence of 10% palladium on activated carbon afforded directly the corresponding methyl 4-biphenylcarboxylates in good yields. By the similar procedure, methyl 4-heteroaryl- and 4-alkyl-substituted benzoates were obtained from heteroaromatic olefins and alkenes, respectively.