Manganese(III) acetate-mediated alkylation of beta-keto esters and beta-keto amides: an enantio- and diastereo-selective approach to substituted pyrrolidinones

beta-Keto esters and beta-keto amides can be efficiently alkylated on reaction with enol ethers and manganese(III) acetate in the presence of copper(II) acetate. These intermolecular radical addition reactions can be used to construct quaternary carbon centres in excellent yield and this method has been utilised in a diastereoselective approach to substituted pyrrolidinones.