Abstract
The zoanthamine alkaloids isolated from the genus Zoanthus species during the last three decades constitute a distinctive family of marine metabolites. These natural products are characterized by the densely functionalized heptacyclic framework, as exemplified by the structures of norzoanthamine (1), zoanthamine (2), and zoanthenol (3), as well as their potent spectrum of unique biological properties such as promising antiosteoporotic properties. Their distinctive biological activities, combined with novel chemical structures, make this family of alkaloids extremely attractive targets for chemical synthesis. However, because of their densely functionalized complex structures, synthetic studies of zoanthamine alkaloids had seriously been impeded until we reached the first total synthesis of norzoanthamine. We describe herein our synthetic approach toward the total synthesis of zoanthamine alkaloids (1-3), focusing on how to tackle and overcome various synthetic challenges.
