Catalytic Asymmetric Construction of α-Quaternary Cyclopentanones and Its Application to the Syntheses of (-)-1,14-Herbertenediol and (-)-Aphanorphine.

A novel and efficient strategy to build α-benzylic quaternary cyclopentanones with excellent enantioselectivities (up to 96 % ee) and high yields (up to 99 % yield) has been developed, and its application demonstrated by the first catalytic asymmetric total synthesis of (-)-1,14-herbertenediol and the formal synthesis of (-)-aphanorphine.