Desymmetrization of Cyclohexadienones via Intramolecular Stetter Reaction to Construct Tricyclic Carbocycles.

N-Heterocyclic carbene catalyzed desymmetrization of cyclohexadienones to construct tricyclic carbocycles via an intramolecular enantioselective Stetter reaction was realized. With 10 mol% of D-camphor-derived triazolium salt E and 10 mol% of KOAc, various substituted tricyclic carbocycles bearing a quaternary carbon stereogenic center and two contiguous stereocenters were obtained in excellent yields with up to 89% ee. [ABSTRACT FROM AUTHOR]