Aziridine-based concise synthesis of (±)-alstonerine

A concise synthesis of the macroline-related alkaloid (±)-alstonerine is reported. Key steps are regioselective and stereospecific aziridine ring-opening using a sulfone-stabilised carbanion, Me3Al-mediated O → N-transacylation–elimination, intramolecular Michael reaction, and one-pot reduction–dehydration–Pictet–Spengler cyclisation.