Abstract: The present invention provides a process for preparing a cephem derivative characterized in that an allenyl .beta.-lactam compound represented by the formula (1) ##STR1## wherein R.sup.1 is amino or protected amino, R.sup.2 is a hydrogen atom or lower alkoxyl, R.sup.3 is a hydrogen atom or carboxylic acid protecting group and X is the group --SO.sub.2 R.sup.4 or --SR.sup.4, R.sup.4 being substituted or unsubstituted aryl or substituted or unsubstituted nitrogen-containing aromatic heterocyclic group is reacted with a nucleophilic agent to obtain the derivative, the cephem derivative being represented by the formula (2) ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above, and Y is the residue of the nucleophilic agent.

Abstract: The present invention provides a process for preparing a 2-exo-methylenepenam derivative represented by the formula (2), the process being characterized by reacting an allenyl .beta.-lactum compound represented by the formula (1) with a metallic reducing agent, in which R.sup.1, R.sup.2, R.sup.3 and X are defined in the specification.

Abstract: The present invention provides a process for preparing a 3-formylcephem derivative represented by the formula (2) ##STR1## which comprises oxidizing in the presence of oxygen a 3-halomethylcephem derivative represented by the formula (1) ##STR2## wherein R.sup.1 is amino group or protected amino group, R.sup.2 is hydrogen atom or a carboxylic acid protective group, X is halogen atom.

Abstract: A process for preparing a .beta.-lactam derivative of formula (2) and/or the corresponding enol tautomer, which includes oxidizing an alkenyl-substituted .beta.-lactam derivative of formula (1) in the presence of a ruthenium catalyst or a rhenium catalyst using a periodic acid: ##STR1## wherein R.sup.1 is a hydrogen atom, a C.sub.1-4 alkyl group or a C.sub.1-4 haloalkyl group, R.sup.2 is a hydrogen atom, a C.sub.1-4 alkyl group or a phenyl group which may have a substituent, A is a group selected from ##STR2## wherein R.sup.3 is an amino group or a protected amino group, and R.sup.4 -R.sup.8 are as defined in the application.

Abstract: This invention provides a method of producing a .beta.-lactam derivative represented by the formula (I): ##STR1## said method consisting essentially of the step of reacting a .beta.-lactam derivative represented by the formula (II): ##STR2## with a phenol in a reaction system which consists essentially of said .beta.-lactam derivative of formula (II) and said phenol.

Abstract: Disclosed is a method of producing a 3-exomethylenecepham of the formula ##STR1## wherein R.sup.1 is amino or substituted amino and R.sup.2 is a carboxy-protecting group comprising reacting a cephem of the formula ##STR2## wherein R.sup.1 and R.sup.2 are as defined above and X is halogen with lead metal while maintaining the pH of the reaction system at about 0.1 to 8. The cephem (I) may be reacted with a catalytic amount of lead metal or a lead compound in the presence of a metal having a greater ionization tendency than lead.

Abstract: The invention provides a process for preparing a .beta.-lactam derivative represented by the formula ##STR1## the process comprising reacting a .beta.-lactam derivative represented by the following formula (II) and having a protected carboxyl group with a cresol; ##STR2## wherein R represents a benzyl group having an electron-donating group as a substituent on the phenyl ring, a diphenylmethyl group which may have an electron-donating group as a substituent on the phenyl ring or a tert-butyl group.

Abstract: The present invention provides a process for preparing a penicillanic acid derivative of the formula ##STR1## which comprises reacting lead with a halogenated penicillanic acid derivative of the formula ##STR2## wherein X, Y, Z and R.sup.1 are as defined in the specification. The reaction is advantageously conducted in the presence of a metal having higher ionization tendency than lead such as aluminum, iron, magnesium or a mixture thereof.

Abstract: Disclosed is a method of producing an optically active .beta.-lactam derivative of the formula ##STR1## comprising irradiating with light, in solid phase, an inclusion complex of a compound of the formula ##STR2## with an optically active host compound.

Abstract: The present invention provides a process for preparing a 1,1-disubstituted ethylene derivative of the formula ##STR1## which comprises reacting lead with a carbinol derivative of the formula ##STR2## wherein R.sup.1, R.sup.2, R.sup.3, X, Y, m and n are defined in the specification. The reaction is conducted more advantageously in the presence of a metal having higher ionization tendency than lead.

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: A process for preparing an azetidinone derivative represented by the formula ##STR1## wherein R.sup.1 is hydrogen, halogen or lower alkoxy, R.sup.2 is hydrogen, halogen, lower alkoxy, amino or a group ##STR2## (in which R.sup.5 is substituted or unsubstituted phenyl, substituted or unsubstituted phenylmethyl, substituted or unsubstituted phenoxymethyl, or substituted or unsubstituted benzoyl), or R.sup.1 and R.sup.2, when taken together, are carbonyl, R.sup.3 is substituted or unsubstituted phenyl, and R.sup.4 is hydrogen, optionally substituted hydrocarbon residue or acyl, silyl, sulfonyl or phosphonyl derived from inorganic acid or organic acid, the process comprising reacting a dithioazetidinone derivative represented by the formula ##STR3## wherein R.sup.1, R.sup.2 and R.sup.4 are as defined above and R.sup.9 is substituted or unsubstituted, nitrogen-containing aromatic heterocyclic residue with a compound represented by the formulaR.sup.3 SO.sub.2 H (VII)wherein R.sup.3 is defined above.

Abstract: A process for preparing an azetidinone derivative represented by the formula (I) ##STR1## wherein R.sup.1 represents an aryl group, arylmethyl group or aryloxymethyl group, R.sup.2 represents hydrogen atom or a carboxyl-protecting group and R.sup.3 represents an alkyl group or aryl group, the process comprising reacting an azetidinone derivative represented by the formula (II) ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above with a chlorinating agent.

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: A process for preparing an azetidinone derivative represented by the formula ##STR1## wherein R.sup.1 is hydrogen, halogen or lower alkoxy, R.sup.2 is hydrogen, halogen, lower alkoxy, amino or a group ##STR2## (in which R.sup.5 is substituted or unsubstituted phenyl, substituted or unsubstituted phenylmethyl, substituted or unsubstituted phenoxymethyl, or substituted or unsubstituted benzoyl), or R.sup.1 and R.sup.2, when taken together, are carbonyl, R.sup.3 is substituted or unsubstituted phenyl, and R.sup.4 is hydrogen, optionally substituted hydrocarbon residue or acyl, silyl, sulfonyl or phosphonyl derived from inorganic acid or organic acid, the process comprising reacting a dithioazetidinone derivative represented by the formula ##STR3## wherein R.sup.1, R.sup.2 and R.sup.4 are as defined above and R.sup.9 is substituted or unsubstituted, nitrogen-containing aromatic heterocyclic residue with a compound represented by the formulaR.sup.3 SO.sub.2 SR.sup.9 (VII)wherein R.sup.3 and R.sup.

Abstract: A process for preparing an azetidinone derivative represented by the formula ##STR1## wherein R.sup.1 is hydrogen, halogen or lower alkoxy, R.sup.2 is hydrogen, halogen, lower alkoxy, amino or a group ##STR2## (in which R.sup.5 is substituted or unsubstituted phenyl, substituted or unsubstituted phenylmethyl, substituted or unsubstituted phenoxymethyl, or substituted or unsubstituted benzoyl), or R.sup.1 and R.sup.2, when taken together, are carbonyl, R.sup.3 is substituted or unsubstituted phenyl, and R.sup.4 is hydrogen, optionally substituted hydrocarbon residue or acyl, silyl, sulfonyl or phosphonyl derived from inorganic acid or organic acid, the process comprising reacting a dithioazetidinone derivative represented by the formula ##STR3## wherein R.sup.1, R.sup.2 and R.sup.4 are as defined above and R.sup.9 is substituted or unsubstituted, nitrogen-containing aromatic heterocyclic residue with a compound represented by the formulaR.sup.3 SO.sub.2 CN (VII)wherein R.sup.3 is defined above.

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: A process for preparing cephalosporin compounds represented by the formula ##STR1## wherein R.sup.1 represents an alkyl group, alkenyl group, substituted or unsubstituted aryl group, substituted or unsubstituted arylmethyl group or substituted or unsubstituted phenoxymethyl group, R.sup.2 represents a carboxyl group or protected carboxyl group, and Y represents the residue of a nucleophilic reagent.