The regioselectivity of the ring opening of 1-activated or nonactivated 2-alkoxycarbonyl or 2-cyanoaziridines by carbanions of the dicarbonyl compounds

Ring opening of title compounds with alkyl malonates, acetylacetone, methyl acetylacetate, and malononitrile was studied. The regioselectivity of the opening depends on several factors. A phenyl group on C? 3 favours C? 3? N bond cleavage, whereas C? 2? N bond cleavage is predominant with C? 3-substituted or C? 2? H aziridines. Cyanoaziridines are predominantly cleaved at C? 3? N. The aziridine configuration at C? 2 and C? 3 is maintained during the cyclisation in pyrrolidones.