A Combined Intramolecular Diels–Alder/Intramolecular Schmidt Reaction: Formal Synthesis of (±)-Stenine

Four stereocenters and three rings are established in one step in a new formal synthesis of (±)-stenine (see scheme). This key reaction cascade consists of an intramolecular Diels–Alder reaction followed by an intramolecular Schmidt reaction. The resulting tricyclic intermediate was readily transformed into a known intermediate en route to stenine, thus completing the formal synthesis.