Aziridines were prepared from α-iodocycloenones in very good yield, by a Michael addition/cyclisation (Gabriel–Cromwell) process employing a slight excess of primary amine and Cs2CO3 as base at 95° C. Using chiral amines it was possible to prepare optically pure aziridines. The same method was also efficient for the synthesis of aziridines from acyclic α- halounsaturated compounds. 2-Oxoazabicycles reacted with several nucleophiles to ...