Intramolecular Heck cyclization to the galanthamine-type alkaloids: total synthesis of (±)-lycoramine

• DOI: 10.1016/j.tet.2004.09.044
• Publication Date: 2004-10-05T15:09:06Z
• Authors: Pi-Hui Liang; Jing-Ping Liu; Ling-Wei Hsin; Chen-Yu Cheng
• Keywords: Furan; Michael reaction; Heck Reaction; Intramolecular reaction; Annulation

Abstract 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.