Abstract: A cephem compound of the formula: wherein R1 stands for an optionally substituted lower alkyl group, R2 stands for H or a lower alkyl group, R3 stands for H, an optionally substituted hydrocarbon group, cyano group, a lower alkyloxy group or a lower alkylthio group, and the ring A stands for an optionally substituted non-quaternarized nitrogen-containing heterocyclic ring, provided that, when A is unsubstituted 2-pyridyl group, R3 stands for a group other than hydrogen, or their esters or salts, has excellent antibacterial activities, oral absorbability and stability, and is useful as an antibacterial agent.

Abstract: Crystalline acetoxymethyl and pivaloyloxymethyl esters of (+)-(5R, 6S)-6-[(R)-1-hydroxyethyl]-3-(3-pyridyl)-7-oxo-4-thia-1-azabicyclo-[3.2.0] hept-2-ene-carboxylic acid can be obtained by adding a poor solvent to a solution of acetoxymethyl or pivaloyloxymethyl ester of (+)-(5R, 6S)-6-[(R)-1-hydroxyethyl]-3-(3-pyridyl)-7-oxo-4-thia-1-azabicyclo-[3.2.0] hept-2-ene-carboxylic acid in a good solvent. The crystalline penem compounds obtained show improved stability and are useful antibacterial agents.

Abstract: Disclosed are an advantageous method of industrial production of tert-butyl 3-oxobutylate, which is a useful intermediate for synthesis, characterized by reacting tert-butyl alcohol with diketene in the presence of 4-(tertiary amino) pyridine, and an industrially advantageous method of producing cephalosporin compounds or pharmaceutically acceptable salts thereof, using tert-butyl 3-oxobutylate as an intermediate.

Abstract: A method for producing 3-(3-oxobutyryloxymethyl)-3-cepham-4-carboxylic acids which are antibiotics or intermediates for the synthesis of antibiotics, at a low temperature in a very short period of time and in good yield, characterized by reacting a 3-hydroxylmethyl-3-cephem-4-carboxylic acid with diketene in the presence of a 4-(tertiary-amino)pyridine and if necessary, when a 7-acylamino-3-(3-oxobutyryloxymethyl)-3-cephem-4-carboxylic acid is obtained, subjecting it to deacylation at the 7-position thereof.

Abstract: Disclosed are an advantageous method of industrial production of tert-butyl 3-oxobutylate, which is a useful intermediate for synthesis, characterized by reacting tert-butyl alcohol with diketene in the presence of 4-(tertiary amino) pyridine, and an industrially advantageous method of producing cephalosporin compounds or pharmaceutically acceptable salts thereof, using tert-butyl 3-oxobutylate as an intermediate.

Abstract: A method for producing a compound of the formula; ##STR1## wherein R stands for a hydrogen atom, an acyl group or a protective group other than acyl groups, Q stands for a hydrogen atom or an ester residue, Y stands for the residue of a nucleophilic compound and the dotted line shows the double bond at 2- or 3- position of the cephem ring or a salt thereof, characterized by allowing a compound of the formula; ##STR2## [R, Q and the dotted line are of the same meaning as above] or a salt thereof to react with a nucleophilic compound or a salt thereof and a compound of the formula; ##STR3## wherein R.sup.1, R.sup.2, R.sup.3 independently stand for a hydrocarbon group having not more than 8 carbon atoms, or R.sup.1 and R.sup.2, R.sup.1 and R.sup.3 or R.sup.2 and R.sup.

Abstract: An advantageous method of producing in large amounts on a commercial scale 2-substituted oxyimino-3-oxobutyric acids, which are useful as intermediates in the synthesis of e.g. aminothiazole cephalosporins, is characterized by reacting a tert-butyl 2-substituted oxyimino-3-oxobutyrate with a hydrogen halide in an anhydrous organic solvent.

Abstract: A method of producing 3-alkanoyloxymethyl-3-cephem-4-carboxylic acids, which are useful as antibiotics or as intermediates in the synthesis of antibiotics, by reacting a 3-hydroxymethyl-3-cephem-4-carboxylic acid with a saturated fatty acid anhydride in an aqueous medium in the presence of an acid-acceptor base and a 4-(tertiary amino)pyridine.

Abstract: A method of producing a 4-halo-2-(substituted or unsubstituted)hydroxyimino-3-oxobutyric acid ester or amide, which is a synthetic intermediate of value for the production of cephalosporins containing an aminothiazole group, characterized by reacting a 2-(substituted or unsubstituted)-hydroxyimino-3-oxobutyric acid or an ester or amide thereof with a silylating agent and reacting the resulting novel 2-(substituted)hydroxyimino-3-silyloxy-3-butenoic acid ester or amide with a halogenating agent.

Abstract: Novel active materials for negative poles in alkaline dry cells, and method of preparing the same are disclosed. Said materials and method do not employ harmful Hg. In place of Hg, an alloy containing at least three elements selected from Bi, Pb, In, Cd, and Ga is used to have a zinc dust alloyed at its outer surfaces with said alloy elements which are afforded with a high hydrogen overvoltage effective to retard the generation of hydrogen due to self erosion of the zinc dust in an alkaline solution of the dry cells.