Total Syntheses of Leuconoxine, Leuconodine B, and Melodinine E by Oxidative Cyclic Aminal Formation and Diastereoselective Ring-Closing Metathesis

Total syntheses of leuconodine B, melodinine E, and leuconoxine were accomplished via a divergent route. The [5.5.6.6]diazafenestrane skeleton was constructed from an indole-3-acetamide derivative via DMDO oxidation to hydroxylindolenine, TMSOTf/2,6-lutidine mediated cyclic aminal formation, and diastereoseletive ring-closing metathesis of a triene derivative.