Antibiotic 5-substituted-3-(2-aminoethylthio)-6-(1-hydroxyethyl)-7-oxo-1-azabicyclo[3 .2.0]hept-2-ene-2-carboxylic acids (I) are disclosed: ##STR1## wherein R is alkyl, cycloalkyl, cycloalkylalkyl, aryl, aralkyl or heteroaryl.
                            抗生素5-取代-3-(2-
氨乙基
硫)-6-(1-羟乙基)-7-氧代-1-
氮杂双环[3 .2.0]庚-2-烯-2-
羧酸(I)被揭示:##STR1##其中R是烷基,环烷基,环烷基烷基,芳香基,芳基烷基或杂环芳基。