The intramolecular cyclization of aziridines with π-nucleophiles can be a useful route to a number of heterocyclic and carbocyclic systems. This methodology has been applied to the synthesis of hexahydro-1H-benzo[c]chromen-1-amines, the basic skeleton of many amaryllidaceae alkaloids. The success of the aziridine cyclization is largely dependent on the N-substitution of aziridine, with activated aziridines not undergoing the cyclization reaction. Only N-H-, N-alkyl- and N-arylaziridines underwent the cyclization reaction. The ring opening of an unactivated aziridines with a π-nucleophile is one of the first examples of such a reaction.
heterocycles - electrophilic additions - ring opening - ethers - amines