Stereoselective Synthesis of Polycycles Containing an Aziridine Group: Intramolecular aza-Diels-Alder Reactions of Unactivated 2H-Azirines with Unactivated Dienes.

Vinyl azide with a pendent diene can undergo thermal decomposition to a related azirine intermediate, which was used immediately in an intramolecular aza-Diels-Alder reaction to furnish an aziridine-containing trans-fused tricyclic core structure with excellent stereoselectivity. The method provides a facile entry to complex polycyclic alkaliods which can be further elaborated by ring-opening reactions and ring expansion of the aziridine moiety, as well as by dihydroxylation of the alkene group.