Abstract: An azetidinone compound represented by the formula ##STR1## wherein R.sup.1 represents a substituted or unsubstituted phenyl group, R.sup.2 represents a carboxyl-protecting group, X represents a hydrogen atom or chlorine atom and Y represents --I, --ONO.sub.2, --OH, ##STR2## or --SR.sup.4 in which R.sup.3 is a lower alkyl group or --OR.sup.5 (wherein R.sup.5 is a halogen-containing lower alkyl group) and R.sup.4 is a substituted or unsubstituted, 5-membered aromatic heterocyclic residue containing sulphur and/or nitrogen atom or atoms.

Abstract: A process for preparing an azetidinone derivative represented by the formula ##STR1## wherein R.sup.1 represents a straight-chain or branched-chain lower alkyl group, substituted or unsubstituted aryl group, substituted or unsubstituted phenylmethyl group or substituted or unsubstituted phenyloxymethyl group, R.sup.2 represents hydrogen atom, an optionally substituted hydrocarbon residue or protective group for amino group selected from the class consisting of acyl, silyl, sulfonyl and phosphonyl derived from organic or inorganic acid, and R.sup.3 represents a substituted or unsubstituted aryl group or the residue of substituted or unsubstituted heterocyclic ring.

Abstract: A 2-substituted cephem derivative represented by the formula ##STR1## wherein R.sup.1 represents a substituted or unsubstituted phenyl group, substituted or unsubstituted phenylmethyl group or substituted or unsubstituted phenoxymethyl group, R.sup.2 represents hydrogen atom or protective group for carboxylic acid and Y represents allyloxy group, benzyloxy group, alkylthio group, carboxyalkylthio group or group of the formula ##STR2## wherein R.sup.4 represents hydrogen atom or lower alkyl group, X represents --O--, --S-- or ##STR3## R.sup.5 represents hydrogen atom, a lower alkyl group or phenyl group and R.sup.6 represents hydrogen atom or lower alkyl group, and a process for preparing the derivatives.

Abstract: This invention provides thiazolinoazetidinone derivatives represented by the formula ##STR1## and processes for preparing the same. The thiazolinoazetidinone derivatives are used as the intermediates for producing cephalosporin compounds useful as antibiotic agents.

Abstract: This invention provides a process for preparing a 2,2-bishalomethylpenam derivative represented by the formula ##STR1## wherein R.sup.1 represents a lower alkyl group, aryl group, arylmethyl group, arylcarbonyl group or aryloxymethyl group, R.sup.2 represents a carboxyl-protecting group, X.sup.1 and X.sup.2 are the same or different and represent a halogen atom, the process being characterized in that a disulfide represented by the formula ##STR2## wherein R.sup.1, R.sup.2 and X.sup.1 are as defined above and R.sup.3 represents an aryl group or heterocyclic group is subjected to an electrolytic reaction in a solvent in the presence of a halogen acid and/or halogen salt.

Abstract: A process for preparing an azetidinone derivative represented by the formula (1) ##STR1## wherein R.sup.1 represents a substituted or unsubstituted aryl group, a substituted or unsubstituted phenylmethyl group or a substituted or unsubstituted phenoxymethyl group, R.sup.2 represents a hydrogen atom or a group for protecting carboxylic acid and Ar represents a substituted or unsubstituted phenyl group, the process comprising reacting a thiazolineazetidinone derivative represented by the formula (2) ##STR2## wherein R.sup.1 and R.sup.2 are as defined above with a sulfonyl bromide represented by the formula (3)Ar--SO.sub.2 --Br (3)wherein Ar is as defined above in water-containing organic solvent.

Abstract: This invention relates to novel thiazolineazetidinone-type compounds represented by the formula ##STR1## wherein R represents a hydrogen atom, alkyl group, alkyl group replaced with halogen atoms, methyl group replaced with substituted or unsubstituted phenyl groups, methyl replaced with halogen atoms, or trialkylsilyl group and Z represents O or Cl.sub.2.

Abstract: This invention provides a process for preparing a 3-exo-methylenecepham derivative represented by the formula ##STR1## wherein R.sup.1 represents an aralkyl or aryloxymethyl group both of which may be substituted on the aromatic ring, and R.sup.2 represents a carboxyl-protecting group, the process comprising subjecting a compound represented by the formula ##STR2## wherein R.sup.1 and R.sup.2 are as defined above, to a cyclization reaction in an acidic water-containing solvent.

Abstract: This invention provides thiazolinoazetidinone derivatives represented by the formula ##STR1## and processes for preparing the same. The thiazolinoazetidinone derivatives are used as the intermediates for producing cephalosporin compounds useful as antibiotic agents.

Abstract: This invention provides a process for preparing a thiazolidine compound of the formula ##STR1## wherein R.sup.1 represents a hydrogen atom, alkyl group, aralkyl group, aryl group or aryloxymethyl group, and R.sup.2 represents a hydrogen atom or a group ##STR2## wherein R.sup.3 represents a hydrogen atom, alkyl group, halogenated alkyl group, benzyl group or silyl group, and X represents a hydrogen atom, halogen atom, hydroxy group, alkoxy group or acyloxy group, the process comprising electrolyzing a thiazoline compound represented by the formula ##STR3## wherein R.sup.1 and R.sup.2 are as defined above, in a mixture comprising a perchloric acid aqueous solution and an organic solvent.

Abstract: This invention provides a process for preparing a .beta.-lactam derivative represented by the formula ##STR1## wherein R.sup.1 represents aralkyl group or aryloxy methyl group, Y represents the group ##STR2## (wherein R.sup.2 represents aryl-substituted lower alkyl group, aryloxy-substituted lower alkyl group or lower alkyl group optionally substituted with halogen atom and X represents halogen atom) or the group ##STR3## (wherein R.sup.2 and X are as defined above), the process comprising electrolyzing an azetidinone derivative of the formula ##STR4## wherein R.sup.1 and R.sup.2 are as defined above in the presence of hydrohalogenic acid and/or halide.

Abstract: This invention provides a process for preparing 2-oxycephalosporin derivative represented by the formula ##STR1## wherein R.sup.1 represents hydrogen atom, acyl group, or lower alkoxycarbonyl group optionally substituted with halogen atom, R.sup.2 represents hydrogen atom, halogen atom or acyloxy group optionally substituted with halogen atom, R.sup.3 represents hydrogen atom, lower alkyl group optionally substituted with halogen atom, or phenyl-lower alkyl group which may be optionally substituted with nitro group, halogen atom or lower alkoxy group on the phenyl ring, and R.sup.4 represents lower primary or secondary alkyl or lower alkylcarbonyl, the process comprising electrolytically oxidizing a cephalosporin derivative represented by the formula ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above, in the presence of a lower carboxylic acid or lower primary or secondary alcohol, and a supporting electrolyte.

Abstract: This invention provides a process for preparing a thiazolinoazetidinone derivative represented by the formula ##STR1## wherein R.sup.1 represents aralkyl group or aryloxymethyl group and R.sup.2 represents acyl group, the process comprising electrolyzing a compound of the formula ##STR2## wherein R.sup.1 is as defined above in the presence of a lower fatty acid.

Abstract: This invention provides a process for preparing an oxazolineazetidinone derivative represented by the formula ##STR1## (wherein R.sup.1 represents hydrogen atom, alkyl group, alkenyl group, substituted or unsubstituted aralkyl group, substituted or unsubstituted aryl group, or substituted or unsubstituted aryloxymethyl group, R.sup.2 represents free or protected carboxyl group and R.sup.3 represents hydrogen atom or methoxy group) from a penicillin derivative represented by the formula ##STR2## wherein R.sup.1, R.sup.2 and R.sub.3 are as defined above.