Straightforward approach to iminoxazines and azetidinimines via 1,4-additions of chelated enolates toward nitroalkenes.

[reaction: see text] Chelated amino acid ester enolates undergo 1,4-addition toward nitroalkenes in a highly stereoselective fashion. Trapping the nitronates formed in the addition step with chloroformates or acyl chlorides gives rise to highly reactive intermediates that directly undergo cyclization. Depending on the N-protecting group (PG) used, iminoxazines or azetidinimines are formed in a simple one-pot protocol.