The invention concerns 7-amino-ceph-3-em-4-carboxylic acid compounds of the formula ##STR1## wherein R.sub.1.sup.a represents hydrogen or an amino protective group R.sub.1.sup.A and R.sub.1.sup.b represent hydrogen or an acyl group Ac, or R.sub.1.sup.A and R.sub.1.sup.b together denote a bivalent amino protective group, and R.sub.2 represents hydrogen or an organic radical R.sub.2.sup.A which together with the --C(.dbd.O)--O-- grouping forms a protected carboxyl group, or salts such compounds which possess salt-forming groups; these compounds have antibiotic properties.
本发明涉及式为##STR1##的7-
氨基头孢-3-
乙烯-4-
羧酸化合物,其中R.sub.1.sup.a代表氢或
氨基保护基R.sub.1.sup.A,R.sub.1.sup.b代表氢或酰基Ac,或R.sub.1.sup.A和R.sub.1.sup.b一起表示双价
氨基保护基,R.sub.2代表氢或有机基团R.sub.2.sup.A,其与--C(.dbd.O)--O--基团一起形成保护羧基,或者具有形成盐的基团的这些化合物的盐。这些化合物具有抗生素性质。