文摘
The conjugate addition of N-BOC-O-benzoyl hydroxylamine catalysed by sodium hydride to a chiral α,β-unsaturated imide gives a 3′-(BOC benzoyloxyaminopropanoyl) derivative. This undergoes cyclization upon treatment with sodium or lithium bases to give a 3′-unsubstituted N-BOC aziridine-2-imide in good yield and diastereoselectivity. When N-BOC-O-benzoyl hydroxylamine is deprotonated with stoichiometric lithium or sodium bases, the intermediate enolate resulting from the 1,4-addition spontaneously undergoes cyclization affording in a single step the N-BOC aziridine in higher yield.