Novel oximes

A compound selected from the group consisting of the syn isomers of 7-(2-amino-4-thiazolyl)-acetamido-cephalosporanic acid of the formula ##STR36## wherein R is selected from the group consisting of hydrogen, chlorine, methoxy, alkyl and alkylthio of 1 to 5 carbon atoms, cycloalkyl of 3 to 5 carbon atoms, acetoxymethyl, carbamoyloxymethyl, ##STR37## AlK is 1 to 4 carbon atoms, azidomethyl and --CH.sub.2 --S--R' and R' is selected from the group consisting of 1,2,3-thiadiazolyl, 1,2,5-thiadiazolyl, 1,2,4-thiadiazolyl, 1,3,4-thiadiazolyl, 1H-tetrazolyl, 1,3-thiazolyl, 1,2,3-triazolyl, 1,2,4-triazolyl, 1,3,4-triazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl or 1,3,4-oxadiazolyl which heteros are optionally substituted with at least one member of the group consisting of methyl, ethyl, propyl, isopropyl, methoxy, ethoxy, propoxy, isopropoxy, amino, hydroxycarbonylmethyl, dimethylaminoethyl and diethylaminoethyl and ##STR38## and AlK is alkyl of up to 5 carbon atoms, acyl of an alkanoic acid of 2 to 4 carbon atoms, 2-oxo-(3H)-thiazolyl-4-yl-carbonyl and 3-methyl-1,2-oxazol-5-yl-carbonyl, n is an integer from 2 to 4 R.sub.1, R.sub.2 and R.sub.3 are individually alkyl of 1 to 4 carbon atoms or together taken with the nitrogen atom they are attached to form a group selected from the group consisting of 1,4-diazobicyclo-(2,2,2)-octan-1-ylium and 1,3,5,7-tetrazatricyclo-(3,3,1,1.sup.3,7) decan-1-ylium and their non-toxic, pharmaceutically acceptable acid addition salts.