One-Pot Synthesis of α-Carbonyl Bicyclic Furans via a Sequential Diels-Alder/5-Exo-Dig Cyclization/Oxidation Reaction.

A new one-pot approach to construct α-carbonyl bicyclic furans from easily accessible diynones is described. This reaction sequence proceeds via a Diels-Alder cycloaddition reaction catalyzed by dimethylaluminum chloride followed by a 5-exo-dig cyclization/oxidation reaction catalyzed by copper(II) chloride. This methodology generates α-carbonyl-functionalized dihydroisobenzofuran derivatives in good to excellent yields.