Sequential Birch reduction–allylation and Cope rearrangement of o-anisic acid derivatives

A new method for the construction of quaternary centers on cycloalkane rings is reported. The Cope rearrangement of 4-methyl-2-allyl-2-(N-pyrrolidinyl)-carboxamide-3-cyclohexenone yields 4-methyl-4-allyl-2-(N-pyrrolidinyl)-carboxamide-2-cyclohexenone in high yield. The rearrangement substrates are easily generated from Birch reduction–allylation of o-anisic acid derivatives.