A Cyclobutanol Ring-Expansion Approach to Oxygenated Carbazoles: Total Synthesis of Glycoborine, Carbazomycin A and Carbazomycin B

Abstract

AbstractThe transition-metal-free total syntheses of the oxygenated carbazole natural products glycoborine, carbazomycin A and carbazomycin B are reported. The key step involves an NBS-mediated cyclobutanol ring expansion to 4-tetralones for the preparation of the tricyclic carbazole core.