Compounds of the formula ##STR1## wherein r.sup.1 is amino or protected amino R.sup.2 is cycloalkenyl X is halogen and Y is carboxy or protected carboxy, or salts useful as intermediates for cephalosporin antibiotics.
公式为##STR1##的化合物,其中r.sup.1为
氨基或保护
氨基,R.sup.2为环烯基,X为卤素,Y为羧基或保护羧基,或其盐,可用作
头孢菌素抗生素的中间体。