Organocatalytic Asymmetric Formal [3+2] Cycloaddition as a Versatile Platform to Access Methanobenzo[7]annulenes

Pharmaceutically and structurally important methanobenzo7]annulenes were synthesized in very good yields with excellent enantio‐ and diastereoselectivities through an unprecedented organocatalytic formal 3+2] cycloaddition from readily available 2‐alkyl‐3‐hydroxynaphthalene‐1,4‐diones and alkyl vinyl ketones.