Synthesis of five-ring-fused azepinone derivatives from bis-isatins via sequential 6π-electrocyclic ring closure, ring expansion, and dehydrogenation process

Abstract

Five-ring-fused azepinone derivatives were synthesized serendipitously frombis-isatins via sequential 6π-electrocyclic ring closure, ring expansion, anddehydrogenation process in moderate yields (34%？47%). The reaction was car-ried out in diphenyl ether at 230 C for 4？12 h under O2balloon atmosphere.