The invention concerns 3-amino-4-(2-hydroxyethylthio)-2-oxo-azetidine compounds of the formula ##STR1## wherein R.sub.1.sup.a represents hydrogen or an amino protective group R.sub.1.sup.A, R.sub.1.sup.b represents hydrogen or an acyl group Ac.sub.1, or R.sub.1.sup.a and R.sub.1.sup.b together denote a bivalent amino protective group, R.sub.2 represents hydrogen or an acyl radical Ac.sub.2, and each of the radicals R.sub.3 and R.sub.4 represents hydrogen or an organic radical bonded via a carbon atom, or salts of such compounds having salt-forming groups.
本发明涉及具有以下式的3-
氨基-4-(2-羟乙
硫基)-2-氧代-氮
杂环化合物:##STR1## 其中,R.sub.1.sup.a表示氢或
氨基保护基R.sub.1.sup.A,R.sub.1.sup.b表示氢或酰基Ac.sub.1,或R.sub.1.sup.a和R.sub.1.sup.b一起表示二价
氨基保护基,R.sub.2表示氢或酰基Ac.sub.2,每个基团R.sub.3和R.sub.4表示通过碳原子连接的氢或有机基团,或具有形成盐的基团的这些化合物的盐。