Abstract
Irradiation of 3-(N-methylanilino)-2H-azirines in dimethoxyethane solution in the presence of dipolarophiles leads to five-membered heterocycles in 40-60% yield. A reaction mechanism via splitting of the C(2),C(3)-bond and formation of a nitrilio methanide which then undergoes a thermal 1,3-dipolar cycloaddition is reasonable.