title: The conversion of 3-exo-methylencephalosporin to 3-halomethylcephems; a convenient synthesis of 3'-substituted cephalosporins from penicillins.
mesh_terms: D002511:Cephalosporins / Q000138:chemical synthesis*; D008722:Methods; D008745:Methylation; D010406:Penicillins
chemical_list: D002511:Cephalosporins; D010406:Penicillins