Mechanism of decarboxylation of bicyclic acids by lead tetra-acetate

Abstract

Oxidative decarboxylation of bicyclo[3.2.1]octane-2-carboxylic acids and bicyclo[2.2.2]octane-2-carboxylic acid by lead tetra-acetate gives mainly acetates by both a carbonium ion and a non-carbonium ion pathway. Analysis of products in the decarboxylation of these and other acids indicates the intermediacy of organolead intermediates, which in the non-carbonium ion route give acetates with retention of stereochemistry. This duality of mechanism is used to explain product distributions reported in earlier studies of related carboxylic acids.