title: beta-lactam antibiotics. Novel synthetic routes to cephem-ring system from beta-lactam thiazolines via hydrazinothioazetidinones.
mesh_terms: D001384:Azetidines; D002511:Cephalosporins / Q000138:chemical synthesis*; D003500:Cyclization; D006835:Hydrazones; D013844:Thiazoles; D047090:beta-Lactams
chemical_list: D001384:Azetidines; D002511:Cephalosporins; D006835:Hydrazones; D013844:Thiazoles; D047090:beta-Lactams