title: Synthesis of 6-methylthiopenicillins and 7-heteroatom-substituted cephalosporins.
mesh_terms: D002511:Cephalosporins / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008722:Methods; D008745:Methylation; D010406:Penicillins / Q000138:chemical synthesis*
chemical_list: D002511:Cephalosporins; D007202:Indicators and Reagents; D010406:Penicillins