Abstract: Cephalosporins of the formula ##STR1## wherein R is hydrogen, sodium, potassium, or certain ester groups; R.sub.1 is in the .alpha.-configuration and is hydrogen or methoxy; R.sub.2 is hydrogen, lower alkyl, cycloalkyl, cycloalkenyl, cycloalkadienyl, substituted or unsubstituted phenyl, benzyl, phenethyl, thienyl, furyl, or pyridyl, or 2-amino-4-thiazolyl; X is --CH.sub.2 --, --CH.sub.2 --CH.sub.2 --, ##STR2## R.sub.3 is hydrogen, ##STR3## --O--lower alkyl, or certain substituted or unsubstituted heterothio groups; are disclosed. These compounds possess useful antibacterial activity.