Synthesis of derivatives of 6H-1,2-oxazine by cyclization of ketoximes with derivatives of terminal acetylene compounds

摘要

A new series of 6H-1,2-oxazines were synthesized by the reaction of ketones with hydroxylamine hydrochloridein the presence of sodium acetate to give ketoximes 1(a-e). Chloramine-T was used as an effective reagent forthe generation of α-nitrosolefins from ketoximes 1(a-e) which subsequently underwent hetero Diels-Alderreaction with terminal acetylenes 4(a-d), to give 6H-1,2-Oxazine derivatives 5(a-t).