Abstract: Cephalosporins derivatives having a 3-position substituent of the formula I are described: ##STR1## wherein R.sup.1 is hydrogen, alkenyl or optionally substituted alkyl, Het is a 5- or 6-membered heterocyclic ring bonded via a carbon atom to the amide linkage, wherein Het is selected from a group of the formulae II-III: ##STR2## wherein A is CH or a nitrogen atom; B is oxygen, sulphur or a group NR.sup.4 ; one or two of D, E, F and G are nitrogen atoms and the remainder are CH groups: or Het is a pyrazinone, pyridinone, pyridazinone or pyrimidinone ring, or is a thione equivalent of such a ring, said rings having a substituent R.sup.4 on one nitrogen atom, or is pyranone, or pyranthione; the ring Het being fused by any two adjacent carbon atoms to the benzene ring; and Het being attached to the --CH.sub.2 NR.sup.1 CO-- group via a carbon atomR.sup.2 is hydroxy or an in vivo hydrolysable ester thereof;R.sup.3 is ortho to R.sup.2 and is hydroxy or an in vivo hydrolysable ester thereof; and R.sup.

Abstract: Cephalosporin derivatives having a 3-position substituent of formula I are described: ##STR1## wherein R.sup.1 is hydrogen, alkenyl or optionally substituted alkyl, Het is a 5- or 6-membered heterocyclic ring bonded via a carbon atom to the amide linkage, wherein Het is selected from a group of the formulae II-III: ##STR2## wherein A is CH or a nitrogen atom; B is oxygen, sulphur or a group NR.sup.4 ; one or two of D, E, F and G are nitrogen atoms and the remainder are CH groups: or Het is a pyrazinone, pyridinone, pyridazinone or pyrimidinone ring, or is a thione equivalent of such a ring, said rings having a substituent R.sup.4 on one nitrogen atom, or is pyranone, or pyranthione; the ring Het being fused by any two adjacent carbon atoms to the benzene ring; and Het being attached to the --CH.sub.2 NR.sup.1 CO-- group via a carbon atom;R.sup.2 is hydroxy or an in vivo hydrolysable ester thereof;R.sup.3 is ortho to R.sup.2 and is hydroxy or an in vivo hydrolysable ester thereof; and R.sup.

Abstract: Cephalosporin antibiotics having a 3-position substituent of the formula:--CH.sub.2 NR.sup.1 --Y--A--Z--Qare described, wherein R.sup.1 is hydrogen or certain optionally substituted alkyl groups; Y is --CO-- or --SO.sub.2 --; A is optionally substituted phenylene or heterocyclylene; Z is a linking group and Q is a catechol or related ring system. Processes for their preparation and use are described.

Abstract: Cephalosporin antibiotics having a 3-position substituent of the formula:--CH.sub.2 NR.sup.1 --Y--A--Z--Qare described, wherein R.sup.1 is hydrogen or certain optionally substituted alkyl groups; Y is --CO-- or --SO.sub.2 --; A is optionally substituted phenylene or heterocyclylene; Z is a linking group and Q is a catechol or related ring system. Processes for their preparation and use are described.

Abstract: Cephalosporin derivatives having a 3-position substituent of the formula I are described: ##STR1## wherein R.sup.1 is hydrogen, alkenyl or optionally substituted alkyl, Het us a 5- or 6-membered heterocyclic ring bonded via a carbon atom to the amide linkage, wherein Het is selected from a group of the formulae II-III: ##STR2## wherein A is CH or a nitrogen atom; B is oxygen, sulphur or a group NR.sup.4 ; one or two of D, E, F and G are nitrogen atoms and the remainder are CH groups: or Het is a pyrazinone, pyridinone, pyridazinone or pyrimidinone ring, or is a thione equivalent of such a ring, said rings having a substituent R.sup.4 on one nitrogen atom, or is pyranone, or pyranthione; the ring Het being fused by any adjacent carbon atoms to the benzene ring; and Het being attached to the --CH.sub.2 NR.sup.1 CO-- group via a carbon atom;R.sup.2 is hydroxy or an in vivo hydrolyzable ester thereof;R.sup.3 is ortho to R.sup.2 and is hydroxy or an in vivo hydrolyzable ester thereof; and R.sup.

Abstract: The invention concerns novel racemic and optically active mono- and di-hydroxy alkanoic acids bearing phenyl and/or alkyl substituents, processes for their preparation, and pharmaceutical compositions for therapeutic use in the treatment of duodenal or gastric ulcers. Representative compounds of the invention are 2-(5.beta.-n-butyl-4.beta.-hydroxy-2-oxo-tetrahydrofuran-3.beta.-yl)-2.alp ha.-methyl-acetic acid and 3.alpha.-methyl-5.beta.-(1.beta.-hydroxy-n-pentyl)-2-oxo-tetrahydrofuran-4 .beta.-ylcarboxylic acid.