Enantioselective access to isoquinuclidines by tropenone desymmetrization and homoallylic radical rearrangement: synthesis of (+)-ibogamine.

[reaction: see text]. Chiral lithium amide-induced desymmetrization of a tropenone and subsequent Bu3SnH-catalyzed nitrogen-directed homoallylic radical rearrangement constitute key steps in a new strategy to dehydroisoquinuclidines. The strategy was applied in a synthesis of (+)-ibogamine