Cephalosporin antibiotics of formula
wherein R is hydrogen, an alkali metal cation, or a carboxylic acid protecting group; R1 is hydrogen or methoxy; R2 is hydrogen or an amino protecting group; R3 is hydrogen or C1-C4 alkyl; and R4 is C1-C4 alkyl.
式中的
头孢菌素类抗生素
其中 R 是氢、碱
金属阳离子或
羧酸保护基;R1 是氢或甲氧基;R2 是氢或
氨基保护基;R3 是氢或 C1-C4 烷基;R4 是 C1-C4 烷基。