Lead-Promoted 2-Carboethoxyallylation or 2-Carboxylallylation of Aldehydes: A New and Facile Method for the Synthesis of α-Methylene-γ-Butyrolactones

Abstract
In the presence of powdered lead, the reaction of aldehydes and α-bromomethylacrylate (or α-bromomethylacrylic acid) can be carried out under mild condition, the products 4-hydroxy-2-methylenebutanoates (or 4-hydroxy-2-methylenebutanoic acids) can be easily converted to α-methylene-γ-butyrolactones in the presence of CF3COOH.