Desymmetrization of Cyclohexadienones via [3+2]/[2+1] Domino Annulation: Access to Cyclopropane Fused Tricyclic Enones

A [3+2]/[2+1] domino annulation reaction of cyclohexadienones and α‐aryl vinylsulfonium salts has been reported. A range of cyclopropane fused tricyclic enones bearing four contiguous stereocenters were obtained as a single diastereomer in 44–93% yields. The synthetic utility was demonstrated with the gram‐scale reactions and further transformations of the products.