SYNTHETIC STUDIES ON NITROGEN-CONTAINING FUSED-HETEROCYCLIC COMPOUNDS BASED ON THERMAL ELECTROCYCLIC REACTIONS OF 6π-ELECTRON AND AZA 6π-ELECTRON SYSTEMS

Syntheses of carbazole alkaloids and indoles by an allene-mediated electrocyclic reaction of a 6 pi-electron system (II) through a tautomeric process, and syntheses of several fused pyridine ring systems including alkaloids by a thermal electrocyclic reaction of an aza 6 pi-electron system having an oxime or isocyanate (III) through either the elimination of a small molecule or a tautomeric process are described.