A novel total synthesis of antibiotic carbazole alkaloid carbazomycin G

A total synthesis of carbazomycin G (1) has been newly completed in seven s teps. The 1,3-dioxygenated carbazole (4) via the 3-methoxy-1-methoxymethylo xycarbazole (11) as a synthetic precursor was synthesized by using the alle ne-mediated electrocyclic reaction of a 6 pi electron system generating fro m the 2-propargylindole derivative (10), which was derived from the 3-vinyl indole (8) in three steps. Finally, the oxidation of the phenol (4) followe d by the addition of methyl lithium to the carbazole-1,4-quinone (3) provid ed carbazomycin G (1). (C) 2000 Elsevier Science Ltd. All rights reserved.