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

Abstract: An azetidinone derivative represented by the formula (I) ##STR1## wherein R.sup.1 is substituted or unsubstituted phenyl or substituted or unsubstituted phenoxy, R.sup.2 is hydrogen, optionally substituted hydrocarbon residue or aminoprotecting group selected from acyl, silyl, sulfonyl and phosphonyl derived from organic or inorganic acid, ##STR2## (wherein R.sup.3 is hydrogen or lower alkyl), X.sup.1 and X.sup.2 are the same or different and are halogen, hydroxyl, alkoxy, acyloxy, SR.sup.4 (wherein R.sup.4 is straight chain or branched chain lower alkyl substituted or unsubstituted, substituted or unsubstituted phenyl or substituted or unsubstituted heterocyclic group), amino or hydrogen, one of X.sup.1 and X.sup.2 being hydrogen when the other is not, and R.sup.5 is substituted or unsubstituted phenyl or substituted or unsubstituted heterocyclic group, and a process for preparing the same.

Abstract: An azetidinone derivative represented by the formula (I) ##STR1## wherein R.sup.1 is substituted or unsubstituted phenyl or substituted or unsubstituted phenoxy, R.sup.2 is hydrogen, optionally substituted hydrocarbon residue or amino-protecting group selected from acyl, silyl, sulfonyl and phosphonyl derived from organic or inorganic acid, ##STR2## is >C.dbd.O or>C.dbd.N--OR.sup.3 (wherein R.sup.3 is hydrogen or lower alkyl), X.sup.1 and X.sup.2 are the same or different and are halogen, hydroxyl, alkoxy, acyloxy, SR.sup.4 (wherein R.sup.4 is straight chain or branched chain lower alkyl substituted or unsubstituted, substituted or unsubstituted phenyl or substituted or unsubstituted heterocyclic group), amino or hydrogen, one of X.sup.1 and X.sup.2 being hydrogen when the other is not, and R.sup.5 is substituted or unsubstituted phenyl or substituted or unsubstituted heterocyclic group, and a process for preparing the same.

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

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

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 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 .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.