Lewis Acid‐Catalyzed Cascade Dehydrative Annulation: Divergent Synthesis of Bi‐ and Tricyclic Frameworks From 2‐Arylethanols and Propargylic Alcohols

ABSTRACT

A Lewis acid‐catalyzed cascade reaction to carbazole, naphthalene, tetrahydropyrano[4,3‐ b ]indole, and isochromane frameworks from readily available 2‐arylethan‐1‐ol and propargylic alcohols is described. A plausible reaction pathway is deduced from the identification and structural analysis of a key intermediate. Furthermore, the scalability of this protocol was demonstrated through a gram‐scale synthesis.