Preparation of Pyrido- and Azepino-fused Cyclazines

Article abstract of DOI:10.1246/bcsj.58.3444

Pyrido-and azepino-fused cycl<3.2.2>azines were obtained by the reaction of the corresponding pyrido-and azepinoindolizines with electron-deficient acetylenes in the presence of appropriate oxidants.The reaction pathway of their preparation was proposed to be a sequence of Michael addition of indolizine to acetylene, 10?-electrocyclic reaction of Michael adduct, and dehydrogenation by means of the chemical conversions of the isolated intermediates.