title: Studies on seven-membered ring compounds. XXII. Preparation of tropylium ions having fused heterocyclic systems.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D006571:Heterocyclic Compounds; D009682:Magnetic Resonance Spectroscopy; D009662:Nortropanes / Q000138:chemical synthesis*
chemical_list: D006571:Heterocyclic Compounds; D009662:Nortropanes