Synthesis of Chiral Tetrahydrofurans by a Palladium-Catalyzed Cycloaddition

Tetrahydrofurans are simple heterocycles found in many natural and synthetic products. It has been previously demonstrated that chiral phosphoramidite ligands can induce enantio-selectivity in many trimethylenemethane (TMM) cycloadditions; however, the synthesis of tetra­hydrofurans from aldehydes had proven to be difficult. The authors report the preparation of chiral methylenetetrahydrofurans by an enantioselective cycloaddition of aldehydes...