Synthesis of 2‐Hydroxy‐7‐methylcarbazole, Glycozolicine, Mukoline, Mukolidine, Sansoakamine, Clausine‐H, and Clausine‐K and Structural Revision of Clausine‐TY

Abstract

Abstract A Buchwald–Hartwig amination and palladium(II)‐catalyzed oxidative cyclization reaction sequence provided efficient access to a series of oxygenated tricyclic carbazoles. In the present work, this approach was applied to the total syntheses of the naturally occurring carbazole alkaloids 2‐hydroxy‐7‐methylcarbazole, glycozolicine, mukoline, mukolidine, sansoakamine, glycozolidine, clausine‐H (clauszoline‐C), clausine‐K (clauszoline‐J), and methyl 2‐hydroxy‐7‐methoxycarbazole‐3‐carboxylate, which was originally proposed as the structure of clausine‐TY. The synthesis of the latter led to the structural reassignment of clausine‐TY.