Abstract: Disclosed are N-alkylated derivatives of thienamycin sulfoxide (I, n=1) and sulfone (I, n=2): ##STR1## wherein n=1 or 2; and R.sup.5, R.sup.6, and R.sup.7 are, inter alia, hydrogen or alkyl. Such compounds the their pharmaceutically acceptable O- and carboxyl- derivatives are useful as antibiotics. Also disclosed are processes for the preparation of such derivatives, pharmaceutical compositions comprising such derivatives and methods of treatment comprising administering such derivatives and compositions when an antibiotic effect is indicated.