A novel approach towards the construction of the galanthamine skeleton was demonstrated by the total synthesis of (±)-lycoramine. The key steps include a Pd-catalyzed intramolecular cyclization to form the seven-membered azepane ring and a spontaneous intramolecular Michael addition to afford the five-membered furan ring. This synthetic route has also been demonstrated to be useful for the preparation of novel derivatives with simplified galanthamine skeletons.
Liang, P-H., Liu, J-P., Hsin, L-W., & Cheng, C-Y. (2004). Intramolecular Heck cyclization to the galanthamine-type alkaloids: total synthesis of (±)-lycoramine. Tetrahedron, 60(50), 11655-11660. https://doi.org/10.1016/j.tet.2004.09.044