Formal Synthesis of Dictyodendrin B

Org Lett. 2023 Apr 21;25(15):2669-2673. doi: 10.1021/acs.orglett.3c00746. Epub 2023 Apr 6.

Abstract

A formal synthesis of dictyodendrin B is described. Regiocontrolled functionalization of the α,β-dibromopyrrole derivative provided the fully substituted pyrrole bearing an indole moiety. Subsequent reductive cyclization using a combination of sodium dispersion and triethylsilyl chloride enabled the formation of the benzene ring in the characteristic tetracyclic pyrrolo[2,3-c]carbazole skeleton, while the ethyl ester remained untouched. Further chemical transformation of the ester moiety and functional group manipulation completed the formal synthesis of dictyodendrin B.