Antibacterial compounds of the formula ##STR1## (where COB is carboxy or protected carboxy; Hal is halogen; R is amino or protected amino; R' is mercapto-protecting group; and X is nucleophilic group) Are prepared from penicillin 1-oxides having X on its 2-methyl group, and found to be used as starting materials for preparing cephalosporins.
公式为##STR1##的抗菌化合物(其中COB是羧基或保护羧基;Hal是卤素;R是
氨基或保护
氨基;R'是巯基保护基;X是亲核基团)是从在其2-甲基基团上具有X的
青霉素1-氧化物制备的,并发现可用作制备
头孢菌素的起始材料。