Abstract: Compounds of the formula ##STR1## wherein R is selected from the group consisting of hydrogen and groups easily removable by acid hydrolysis or hydrogenolysis, R' is selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms, alkenyl and alkynyl of 2 to 4 carbon atoms and groups easily removable by acid hydrolysis or hydrogenolysis, A is selected from the group consisting of hydrogen, alkali metal and equivalents of an alkaline earth metal or magnesium and an organic amine base with the proviso that when R' is a group easily removable by acid hydrolysis or hydrogenolysis, R is also and when R' is hydrogen, R also is hydrogen and the wavy line means the OR' group may be in either one of the two possible syn or anti positions having antibiotic activity and process for their preparation.

Abstract: Compounds of the formula ##STR1## wherein R is selected from the group consisting of hydrogen and groups easily removable by acid hydrolysis of hydrogenolysis, R' is selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms, alkenyl and alkynyl of 2 to 4 carbon atoms and groups easily removable by acid hydrolysis or hydrogenolysis. A is selected from the group consisting of hydrogen, alkali metal and equivalents of an alkaline earth metal or magnesium and an organic amine base with the proviso that when R' is a group easily removable by acid hydrolysis of hydrogenolysis, R is also and when R' is hydrogen, R also is hydrogen and the wavy line means the OR' group may be in either one of the two possible syn or anti positions having antibiotic activity and process for their preparation.

Abstract: Compounds of the formula ##STR1## wherein R is selected from the group consisting of hydrogen and groups easily removable by acid hydrolysis or hydrogenolysis, R' is selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms, alkenyl and alkynyl of 2 to 4 carbon atoms and groups easily removable by acid hydrolysis or hydrogenolysis, A is selected from the group consisting of hydrogen, alkali metal and equivalents of an alkaline earth metal or magnesium and an organic amine base with the proviso that when R' is a group easily removable by acid hydrolysis or hydrogenolysis, R is also and when R' is hydrogen, R also is hydrogen and the wavy line means the OR' group may be in either one of the two possible syn or anti positions having antibiotic activity and process for their preparation.

Abstract: Novel alkyloximes of 7-amino-thiazolyl-acetamido-cephalosporanic acids of the formula ##STR1## wherein R is selected from the group consisting of alkyl of 1 to 5 carbon atoms, cycloalkyl of 3 to 5 carbon atoms and --CH.sub.2 --SR', R' is selected from the group consisting of acyl of an alkanoic acid of 2 to 4 carbon atoms, 1-methyl-tetrazolyl and 2-methyl-1,3,4-thiadiazolyl, R.sub.1 is selected from the group consisting of hydrogen and a group easily removeable by acid hydrolysis or hydrogenolysis, R.sub.2 is selected from the group consisting of alkyl of 1 to 4 carbon atoms and alkenyl and alkynyl of 2 to 4 carbon atoms, A is selected from the group consisting of hydrogen, an alkali metal cation, an equivalent of an alkaline earth metal or magnesium, or organic amine base cation and an ester group easily removeable by acid hydrolysis or hydrogenolysis with the proviso that when R.sub.1 is hydrogen, A is not an ester group easily removeable by hydrogenolysis or acid hydrolysis and the wavy line means that OR.

Abstract: Novel syn isomers of oximes of 3-azidomethyl-7-amino-thiazolyl-cephalosporanic acids of the formula ##STR1## wherein R is selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms, unsaturated alkyl of 2 to 4 carbon atoms, benzoyl and --(CH.sub.2).sub.n --R.sub.1, n is an integer from 1 to 4, R.sub.1 is selected from the group consisting of NH.sub.2 and --COOA' and A' and A are selected from the group consisting of hydrogen, alkali metal, alkaline earth metal, magnesium, --NH.sub.4, an easily cleavable ester group and a non-toxic, pharmaceutically acceptable organic amine and their non-toxic, pharmaceutically acceptable acid addition salts having antibiotic activity and a novel process and novel intermediates for their preparation.

Abstract: Novel alkyloximes of 7-amino-thiazolyl-acetamide-cephalosporanic acids of the formula ##STR1## wherein R is selected from the group consisting of alkyl of 1 to 5 carbon atoms, cycloalkyl of 3 to 5 carbon atoms and --CH.sub.2 --SR', R' is selected from the group consisting of acyl of an alkanoic acid of 2 to 4 carbon atoms, 1-methyl-tetrazolyl and 2-methyl-1,3,4-thiadiazolyl, R.sub.1 is selected from the group consisting of hydrogen and a group easily removeable by acid hydrolysis or hydrogenolysis, R.sub.2 is selected from the group consisting of alkyl of 1 to 4 carbon atoms and alkenyl and alkynyl of 2 to 4 carbon atoms, A is selected from the group consisting of hydrogen, an alkali metal cation, an equivalent of an alkaline earth metal or magnesium, an organic amine base cation and an ester group easily removeable by acid hydrolysis or hydrogenolysis with the proviso that when R.sub.1 is hydrogen, A is not an ester group easily removeable by hydrogenolysis or acid hydrolysis and the wavy line means that OR.

Abstract: Compounds of the formula ##STR1## wherein R is selected from the group consisting of hydrogen and groups easily removable by acid hydrolysis or hydrogenolysis, R' is selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms, alkenyl and alkynyl of 2 to 4 carbon atoms and groups easily removable by acid hydrolysis or hydrogenolysis, A is selected from the group consisting of hydrogen, alkali metal and equivalents of an alkaline earth metal or magnesium and an organic amine base with the proviso that when R' is a group easily removable by acid hydrolysis or hydrogenolysis, R is also and when R' is hydrogen, R also is hydrogen and the wavy line means the OR' group may be in either one of the two possible syn or anti positions having antibiotic activity and process for their preparation.

Abstract: Novel syn isomers of 7-[2-(2-amino-4-thiazolyl)-2-(carboxymethyloxyimino)-acetamido]-ceph-3-eme -4-carboxylic acid compounds of the formula ##STR1## wherein R is selected from the group consisting of alkyl of 1 to 3 carbon atoms and --CH.sub.2 --S--R.sub.1, R.sub.1 is an optionally substituted heterocyclic of 5 to 6 chain components with 1 to 4 heteroatoms selected from the group consisting of oxygen, sulfur and nitrogen, A is selected from the group consisting of hydrogen, alkali metal, alkaline earth metal, magnesium, --NH.sub.4, an easily cleavable ester and a non-toxic, pharmaceutically acceptable organic amine, A.sub.1 is selected from the group consisting of alkyl of 1 to 3 carbon atoms, hydrogen, alkali metal, alkaline earth metal, magnesium, --NH.sub.4, an easily cleavable ester and a non-toxic, pharmaceutically acceptable organic amine and non-toxic, pharmaceutically acceptable acid addition salts thereof having antibiotic activity and their preparation and intermediates therefor.

Abstract: Novel erythromycin derivatives in the syn form or anti form or mixtures of the syn and anti forms of the formula ##STR1## wherein A is a linear or branched alkylene of 1 to 6 carbon atoms, R is selected from the group consisting of optionally substituted alkoxy of 1 to 6 carbon atoms, optionally substituted alkenyloxy and alkynyloxy of 2 to 6 carbon atoms, optionally substituted alkylthio of 1 to 6 carbon atoms, optionally substituted alkenylthio and alkynylthio of 2 to 6 carbon atoms with the thio group optionally oxidized to the sulfoxide or sulfone form, optionally substituted aryloxy and arylthio, optionally substituted aralkyloxy and arylalkylthio, the thio derivatives optionally oxidized to sulfoxide or sulfone, ##STR2## optionally substituted quaternary ammonium group, halogen, optionally substituted 1,2-epoxyethyl and the group resulting from opening of the epoxy with a nucleophilic reactant, ##STR3## a free or protected formyl, --COOR', thiocyanate, --CN, acyl and carbamoyl, R.sub.1 and R.sub.

Abstract: Novel syn isomers of 3-substituted-7-amino-thiazolyl-acetamido-cephalosporanic acid compounds of the formula ##STR1## wherein R is selected from the group consisting of alkyl of 1 to 5 carbon atoms, cycloalkyl of 3 to 5 carbon atoms and --CH.sub.2 --S--R.sub.1, R.sub.1 is selected from the group consisting of 2-methyl-1,3,4-thiadiazolyl, 1-methyl tetrazolyl, acyl of an organic carboxylic acid of 2 to 4 carbon atoms and ##STR2## R.sub.2 is selected from the group consisting of alkyl and alkoxy of 1 to 4 carbon atoms and A is selected from the group consisting of hydrogen, alkali metal, alkaline earth metal, magnesium and a non-toxic, pharmaceutically acceptable organic amine having antibiotic activity and novel intermediates and process for their preparation.

Abstract: Novel syn isomers of 7-[2-(2-amino-4-thiazolyl)-2-(carboxymethyloxyimino)-acetamido]-ceph-3-eme -4-carboxylic acid compounds of the formula ##STR1## wherein R is selected from the group consisting of alkyl of 1 to 3 carbon atoms and --CH.sub.2 --S--R.sub.1, R.sub.1 is an optionally substituted heterocyclic of 5 to 6 chain components with 1 to 4 heteroatoms selected from the group consisting of oxygen, sulfur and nitrogen, A is selected from the group consisting of hydrogen, alkali metal, alkaline earth metal, magnesium, --NH.sub.4, an easily cleavable ester and a non-toxic, pharmaceutically acceptable organic amine, A.sub.1 is selected from the group consisting of alkyl of 1 to 3 carbon atoms, hydrogen, alkali metal, alkaline earth metal, magnesium, --NH.sub.4, an easily cleavable ester and a non-toxic, pharmaceutically acceptable organic amine and non-toxic, pharmaceutically acceptable acid addition salts thereof having antibiotic activity and their preparation and intermediates therefor.

Abstract: Compounds of the formula ##STR1## wherein R is selected from the group consisting of hydrogen and groups easily removable by acid hydrolysis or hydrogenolysis, R' is selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms, alkenyl and alkynyl of 2 to 4 carbon atoms and groups easily removable by acid hydrolysis or hydrogenolysis, A is selected from the group consisting of hydrogen, alkali metal and equivalents of an alkaline earth metal or magnesium and an organic amine base with the proviso that when R' is a group easily removable by acid hydrolysis or hydrogenolysis, R is also and when R' is hydrogen, R also is hydrogen and the wavy line means the OR' group may be in either one of the two possible syn or anti positions having antibiotic activity and process for their preparation.

Abstract: Novel syn isomers of 3-substituted-7-amino-thiazolyl-acetamido-cephalosporanic acid compounds of the formula ##STR1## wherein R is selected from the group consisting of alkyl of 1 to 5 carbon atoms, cycloalkyl of 3 to 5 carbon atoms and --CH.sub.2 --S--R.sub.1, R.sub.1 is selected from the group consisting of 2-methyl-1,3,4-thiadiazolyl, 1-methyl tetrazolyl, acyl of an organic carboxylic acid of 2 to 4 carbon atoms and ##STR2## R.sub.2 is selected from the group consisting of alkyl and alkoxy of 1 to 4 carbon atoms and A is selected from the group consisting of hydrogen, alkali metal, alkaline earth metal, magnesium and a non-toxic, pharmaceutically acceptable organic amine having antibiotic activity and novel intermediates and process for their preparation.

Abstract: A compound of the formula ##STR1## wherein R is selected from the group consisting of hydrogen and a group easily removable by acid hydrolysis or hydrogenolysis, R.sub.1 is selected from the group consisting of hydrogen and alkyl of 1 to 4 carbon atoms and A is selected from the group consisting of hydrogen, alkali metal, an equivalent of alkaline earth metal and magnesium and an organic amine base having antibiotic properties and a process for their preparation and novel intermediates.

Abstract: Novel alkyloximes of 7-amino-thiazolyl-acetamidocephalosporanic acids of the formula ##STR1## wherein R is selected from the group consisting of alkyl of 1 to 5 carbon atoms, cycloalkyl of 3 to 5 carbon atoms and --CH.sub.2 --SR', R' is selected from the group consisting of acyl of an alkanoic acid of 2 to 4 carbon atoms, 1-methyl-tetrazolyl and 2-methyl-1,3,4-thiadiazolyl, R.sub.1 is selected from the group consisting of hydrogen and a group easily removeable by acid hydrolysis or hydrogenolysis, R.sub.2 is selected from the group consisting of alkyl of 1 to 4 carbon atoms and alkenyl and alkynyl of 2 to 4 carbon atoms, A is selected from the group consisting of hydrogen, an alkali metal cation, an equivalent of an alkaline earth metal or magnesium, an organic amine base cation and an ester group easily removeable by acid hydrolysis or hydrogenolysis with the proviso that when R.sub.1 is hydrogen, A is not an ester group easily removeable by hydrogenolysis or acid hydrolysis and the wavy line means that OR.

Abstract: Compounds of the formula ##STR1## wherein R is hydrogen, R' is selected from the group consisting of alkenyl and alkynyl of 2 to 4 carbon atoms, A is selected from the group consisting of hydrogen, alkali metal and equivalents of an alkaline earth metal or magnesium and an organic amine base and the OR' group is in the syn position having antibiotic activity and process for their preparation.

Abstract: Compounds of the formula ##STR1## wherein R is selected from the group consisting of hydrogen and groups easily removable by acid hydrolysis or hydrogenolysis, R' is selected from the group consisting of hydrogen, alkyl of 1 to 4 carbon atoms, alkenyl and alkynyl of 2 to 4 carbon atoms and groups easily removable by acid hydrolysis or hydrogenolysis, A is selected from the group consisting of hydrogen, alkali metal and equivalents of an alkaline earth metal or magnesium and an organic amine base with the proviso that when R' is a group easily removable by acid hydrolysis or hydrogenolysis, R is also and when R' is hydrogen, R also is hydrogen and the wavy line means the OR' group may be in either one of the two possible syn or anti positions having antibiotic activity and process for their preparation.

Abstract: Cephalosporan compounds of the formula ##STR1## in the form of racemic mixtures or optically active isomers or in the form of their cis or trans isomers or mixtures thereof wherein R is selected from the group consisting of phenyl substituted with at least one hydroxyl and sydnone optionally substituted with phenyl, R' is selected from the group consisting of hydrogen and R", R" is an ester group easily removable by acid hydrolysis or hydrogenolysis, R.sub.1 and R.sub.2 are alkyl of 1 to 3 carbon atoms, R.sub.3 is selected from the group consisting of hydrogen and alkyl of 1 to 3 carbon atoms, Y is selected from the group consisting of amino and Y', Y' is hydrogen and NHCOOZ, Z is straight or branched alkyl of 1 to 5 carbon atoms and their non-toxic, pharmaceutically acceptable addition salts with organic and inorganic acids and bases where appropriate with the proviso that when Y is amino, R' is hydrogen and when Y is amino or NHCOOZ, R is phenyl which have antibacterial activity and their preparation.

Abstract: Cephalosporon compounds of the formula ##SPC1##In the form of racemic mixtures or optically active isomers or in the form of their cis or trans isomers or mixtures thereof wherein R is selected from the group consisting of phenyl substituted with at least one hydroxyl and sydnone optionally substituted with phenyl, R' is selected from the group consisting of hydrogen and R", R" is an ester group easily removable by acid hydrolysis or hydrogenolysis, R.sub.1 and R.sub.2 are alkyl of 1 to 3 carbon atoms, R.sub.3 is selected from the group consisting of hydrogen and alkyl of 1 to 3 carbon atoms, Y is selected from the group consisting of amino and Y', Y' is hydrogen and NHCOOZ, Z is straight or branched alkyl of 1 to 5 carbon atoms and their non-toxic, pharmaceutically acceptable addition salts with organic and inorganic acids and bases where appropriate with the proviso that when Y is amino, R' is hydrogen and when Y is amino or NHCOOZ, R is phenyl which have antibacterial activity and their preparation.