ChemInform Abstract: Synthesis of Spirocyclic 1,3‐Oxazines via Three‐Component Reactions of α,β‐Unsaturated N‐Arylaldimines, Dialkyl Acetylenedicarboxylate and Quinones.

Abstract

Abstract A series of structurally diverse spirocyclic 1,3-oxazines were conveniently prepared from three-component reactions of α,β-unsaturated N-arylaldimines, dialkyl acetylenedicarboxylate and quinones in dry acetonitrile without catalyst. Various quinones including p-benzoquinone, 1,4-naphthoquinone, acenaphthenequinone, and phenanthrenequinone as well as benzil were successfully used in the reaction to give the corresponding spirocyclic 1,3-oxazines in good yields. The diastereoisomers of the obtained spirocyclic 1,3-oxazines were elucidated by 1H NMR spectra and single crystal structures.