title: The removal and displacement of the thiazolidine ring of penicillin. 3. Reconstruction of the penam ring system.
mesh_terms: D002511:Cephalosporins; D003500:Cyclization; D004735:Energy Transfer; D007202:Indicators and Reagents; D008628:Mercury; D000432:Methanol; D010406:Penicillins; D011522:Protons; D013329:Structure-Activity Relationship
chemical_list: D002511:Cephalosporins; D007202:Indicators and Reagents; D010406:Penicillins; D011522:Protons; D008628:Mercury; D000432:Methanol