A biomimetic approach for the concise total synthesis of greenwaylactams A–C

A concise, racemic total synthesis of three sesquiterpenoid alkaloids (greenwaylactams A–C) exhibiting an unprecedented 8-membered benzolactam is disclosed. Key transformations of this work include the ring expansion through cleavage of an indole via Witkop oxidation, as well as an HFIP mediated cationic cyclisation to build up the pentacyclic carbon skeleton.