Novel cage compounds from inter- and intra-molecular Diels–Alder reactions of heteroaromatic azadienes and methyl coumalate with cyclo-octa-1,5-diene

Abstract

1,2,4-Triazines, pyridazines, and α-pyrones activated with electron-withdrawing groups were found to react with cyclo-octa-1,5-diene by intermolecular Diels–Alder addition followed by extrusion of nitrogen or carbon dioxide; the resulting 2-aza-1,3-dienes or 1,3-dienes then undergo intramolecular ring-closure reactions to produce novel cage compounds.