Metal‐Free Rapid Diastereoselective Construction of Isocryptolepine Core via Elecrophilic Dearomatization ‐ Inramolecular Michael Addition Sequence

Abstract A method for rapid construction of indolo[3,2‐ l ]acridin‐7‐one systems bearing isocryptolepine scaffold is described. Metal‐free condensation of (4‐methoxyphenyl)cyclohexan carbinols with ortho‐amino/hydroxybenzonitriles in concentrated sulfuric acid yields polyannulated compounds with four new stereogenic centers in a highly diastereoselective manner. The reaction includes elecrophilic dearomatization of methoxyarene, formation of spirocyclic intermediate and intramolecular 1,4‐nucleophilic addition sequence.