The biologically active carbazole alkaloids, carquinostatin A were isolated from Streptomyces chromo fuscus by Seto and co-workers in 1993. This compound was shown to be a potent neuronal cell protecting substance which exhibits a free radical scavenging activity. We report the asymmetric synthesis of the highly substituted carbazole alkaloid, carquinostatin A. The key step is a construction of the appropriate carbazole framework based on an allene-mediated electrocyclic reaction of the 6Π-electron system involving the indole 2,3-bond followed by lipase QLM catalyzed enantioselective acetylation of the racemic alcohol that the (-)-acetate and (+)-alcohol was obtained with high enantioselectivity, respectively.
