Unified Total Syntheses of (±)-Sessilifoliamides B, C, and D

The first total syntheses of the Stemona alkaloids sessilifoliamides B and D and the second synthesis of sessilifoliamide C have been completed from a simple pyrrole substrate. The bicyclic lactam core was prepared on a gram scale via a Bronsted acid mediated cyclization and controlled oxidation with Dess-Martin periodinane. This delivered sessilifoliamide C (and its C-11 epimer) in 24% yield over 11 steps, and sessilifoliamides B and D in 13 and 17 steps, respectively.

Automated summary

The total syntheses of Stemona alkaloids sessilifoliamides B and D, as well as the second synthesis of sessilifoliamide C, were successfully completed from a simple pyrrole substrate. The bicyclic lactam core was prepared on a gram scale via a Bronsted acid mediated cyclization and controlled oxidation with Dess-Martin periodinane. Yield percentages for the synthesis of sessilifoliamides B, C, and D were 24%, 13%, and 17% respectively, over multiple steps.