title: Syntheses based on 1,2-secopenicillins. Part 4. A new  tricyclic beta-lactam derivative.
mesh_terms: D001381:Azepines / Q000138:chemical synthesis; D001384:Azetidines; D003500:Cyclization; D007536:Isomerism; D010406:Penicillins; D014230:Triazoles / Q000138:chemical synthesis; D047090:beta-Lactams / Q000138:chemical synthesis*
chemical_list: D001381:Azepines; D001384:Azetidines; D010406:Penicillins; D014230:Triazoles; D047090:beta-Lactams