An efficient Au-catalyzed synthesis of isomukonidine, clausine L, mukonidine, glycosinine, mukonal, and clausine V from propadienyl methyl ether

Naturally occurring carbazole alkaloids such as isomukonidine, clausine L, mukonidine, glycosinine, mukonal, and clausine V have been synthesized through a gold-catalyzed cyclization reaction of 1-(indol-2-yl)-2-methoxy-2,3-allenols, which are readily available from indolecarbaldehydes and methoxypropadiene. Compared to the reported procedures, our approach is general, atom economic, highly selective, and the starting materials are easily available.