3-(Substituted) vinyl cephalosporins

A compound of the formula ##STR32## wherein n is 0 or 1;

• R is hydrogen, cyanoacetyl or a group of the formula ##STR33## wherein Ar is 2-thienyl, 3-thienyl, 2-furyl, 3-furyl, 2-pyrrolyl, 3-pyrrolyl, phenyl, or nitrophenyl;
• ##STR34## wherein X is oxygen or sulfur and Ar is as defined above;
• ##STR35## wherein Ar is as defined above and B is --OH, or such --OH group protected by esterification with a C.sub.1 -C.sub.6 alkanoic acid;
• or
• B is --COOH, or such --COOH group protected by esterification with a C.sub.1 -C.sub.6 alkanol;
• or B is ##STR36## --NH-SO.sub.3 H, or --C(O)-NH.sub.2 ;
• R.sup.1 is hydrogen, or
• R and R.sup.1 taken together with the nitrogen to which they are bonded denote --NH.sub.3.sup.+, a salt group with an acid having a pKa of less than 4, or a cyclic imide group from a C.sub.3 to C.sub.12 hydrocarbon dicarboxylic acid;
• R.sup.2 is hydrogen,
• C.sub.4 to C.sub.6 -tert-alkyl,
• C.sub.5 to C.sub.7 -tert-alkenyl,
• C.sub.5 to C.sub.7 -tert-alkynyl, or
• a pharmaceutically acceptable cation;
• and
• Y is --C(O)OR.sup.3 where R.sup.3 is C.sub.1 -C.sub.4 alkyl, --CN, --COOH, --CHO, --X-C.sub.1 to C.sub.4 alkyl wherein X is oxygen or sulfur, --C(O)-NH.sub.2, --NO.sub.2, --S(O)-C.sub.1 C.sub.4 alkyl, --S(O).sub.2 C.sub.1 -C.sub.4 alkyl, or Cl, Br, or trifluoromethyl.