Abstract: Intermediates for preparaing an antibacterial 1-dethia-1-oxacephalosporins which are represented by the following formula: ##STR1## wherein R is a monovalent group (minus the carbonyl) from an acyl derived from a carboxylic or carbonic acid;Y.sup.1 is a divalent group of the following formula: ##STR2## wherein COB is carboxy or protected carboxy;X is hydrogen or a nucleophilic group; andZ is a leaving groupare prepared from a compound of the following formula: ##STR3## wherein R and Y.sup.1 are as defined aboveby the action of an acid.The new compounds of this invention shown by the following formula: ##STR4## wherein A is amino or substituted amino;E is hydrogen or methoxy; andY is a divalent group of the following formula: ##STR5## in which COB, X, and Z are as defined above are convertible into other compounds of the same formula by applying conventional methods in .beta.-lactam chemistry.

Abstract: Intermediates of the following formula are useful for the synthesis of 1-oxacephalosporins. Their preparation from penicillins and the transformation process to make 1-oxacephalosporins are disclosed. The compounds are of the formula: ##STR1## wherein A is amino or a selected acylamino;COB is carboxy or a selected protected-carboxy;X is halogen or the group ORin which R is a group represented by following formulas: ##STR2## wherein Nu is a selected nucleophilic group; R.sup.1 is a group of the following formula: ##STR3## in which Hal is halogen or alkylsulfonyloxy and R.sup.2 is alkyl or aryl; andY is hydrogen or methoxy; with the proviso that when R is propargyl or 2-oxopropyl andR.sup.1 is ##STR4## A is in the 3.alpha.-configuration and Y is 3.beta.-hydrogen or A is in the 3.beta.-configuration and Y is 3.alpha.-methoxy.

Abstract: N-Acetyl-.beta.-D-glucosaminides produced from 1-chloro-1-deoxy-2,3,4,6-tetraacetyl-.alpha.-D-glucosamine and indicators for titration as the aglycons useful as substrates in kits for diagnostic aid, with which N-acetyl-.beta.-D-glucosaminidase activity can be determined colorimetrically in high sensitivity, precisely, and quickly.

Abstract: Intermediates for preparing an antibacterial 1-dethia-1-oxacephalosporins which are represented by the following formula: ##STR1## wherein R is a monovalent group (minus the carbonyl) from an acyl derived from a carboxylic or carbonic acid;Y.sup.1 is a divalent group of the following formula: ##STR2## wherein COB is carboxy or protected carboxy;X is hydrogen or a nucleophilic group; andZ is a leaving groupare prepared from a compound of the following formula; ##STR3## wherein R and Y.sup.1 are as defined above by the action of an acid. The new compounds of this invention shown by the following formula: ##STR4## wherein A is amino or substituted amino;E is hydrogen or methoxy; andY is a divalent group of the following formula: ##STR5## in which COB, X, and Z are as defined above are convertible into other compounds of the same formula by applying conventional methods in .beta.-lactam chemistry.

Abstract: A compound of the formula: ##STR1## wherein u represents hydrogen, carboxamido, N-hydroxycarboxamido, carboxy, azido, an aryl, an acylamino, a protected carboxy or an N-alkoxycarboxamido, or, together with v, can represent --S-- or --CH.sub.2 S--; v represents hydrogen, halogen, cyano or an alkylthio, or, together with u, can represent --S-- or --CH.sub.2 S--, or, together with w, can represent --(CH.sub.2).sub.3 CO--; w represents hydrogen, carboamoyl, cyano, carboxy, an N-alkylcarbamoyl, an alkyl, an aryl, a protected carboxy or a heterocycle, or, together with v, can represents --(CH.sub.2).sub.

Abstract: Intermediates for preparing an antibacterial 1-dethia-1-oxacephalosporins which are represented by the following formula: ##STR1## wherein R is a monovalent group (minus the carbonyl) from an acyl derived from a carboxylic or carbonic acid;Y.sup.1 is a divalent group of the following formula: ##STR2## wherein COB is carboxy or protected carboxy;X is hydrogen or a nucleophilic group; andZ is a leaving groupare prepared from a compound of the following formula: ##STR3## wherein R and Y.sup.1 are as defined above by the action of an acid.

Abstract: Intermediates for preparing an antibacterial 1-dethia-1-oxa-cephalosporins which are represented by the following formula: ##STR1## wherein R is a monovalent group (minus the carbonyl) from an acyl derived from a carboxylic or carbonic acid;Y.sup.1 is a divalent group of the following formula: ##STR2## wherein COB is carboxy or protected carboxy;X is hydrogen or a nucleophilic group; andZ is a leaving groupare prepared from a compound of the following formula: ##STR3## wherein R and Y.sup.1 are as defined above by the action of an acid.

Abstract: Intermediates for preparing an antibacterial 1-dethia-1-oxacephalosporins which are represented by the following formula: ##STR1## wherein R is a monovalent group (minus the carbonyl) from an acyl derived from a carboxylic or carbonic acid;Y.sup.1 is a divalent group of the following formula: ##STR2## wherein COB is carboxy or protected carboxy;X is hydrogen or a nucleophilic group; andZ is a leaving groupare prepared from a compound of the following formula: ##STR3## wherein R and Y.sup.1 are as defined above by the action of an acid. The new compounds of this invention shown by the following formula: ##STR4## wherein A is amino or substituted amino;E is hydrogen or methoxy; andY is a divalent group of the following formula: ##STR5## in which COB, X, and Z are as defined above are convertible into other compounds of the same formula by applying conventional methods in .beta.-lactam chemistry.

Abstract: An intermediate represented by following formula for synthesizing 3-hydroxy-3-cephem compounds. ##STR1## wherein A and B each is a hydrogen or amine substituent; R is a hydrogen or thiol substituent; Nal is a halogen; X is a hydroxy or carboxy protecting group; the broken line between A and R shows that when R and B are hydrogens, and A is a carboxylic acyl, the substituents can be combined to form an azetidimethiazoline bicyclic ring; and the enamine derivatives thereof.

Abstract: N-Acetyl-.beta.-D-glucosaminides produced from 1-chloro-1-deoxy-2,3,4,6-tetraacetyl-.alpha.-D-glucosamine and indicators for titration as the aglycons useful as substrates in kits for diagnostic aid, with which N-acetyl-.beta.-D-glucosaminidase activity can be determined colorimetrically in high sensitivity, precisely, and quickly.

Abstract: Intermediates for preparing an antibacterial 1-dethia-1-oxacephalosporins which are represented by the following formula: ##STR1## wherein R is a monovalent group (minus the carbonyl) from an acyl group derived from a carboxylic or carbonic acid;Y.sup.1 is a divalent group of the following formula: ##STR2## wherein COB is carboxy or protected carboxy;X is hydrogen or a nucleophilic group; andZ is a leaving group are prepared from a compound of the following formula: ##STR3## wherein R and Y.sup.1 are as defined above by the action of an acid. The new compounds of this invention shown by the following formula: ##STR4## wherein A is amino or substituted amino;E is hydrogen or methoxy; andY is a divalent group of the following formula: ##STR5## in which COB, X, and Z are as defined above are convertible into other compounds of the same formula by applying conventional methods in .beta.-lactam chemistry.

Abstract: An intermediate represented by following formula for synthesizing 3-hydroxy-3-cephem compounds ##STR1## wherein A and B each is a hydrogen or amino substituent; R is a hydrogen or thiol substituent; Hal is a halogen; X is a hydroxy or carboxy protecting group; the broken line between A and R shows that when R and B are hydrogens, and A is a carboxylic acyl, the substituents can be combined to form an azetidinothiazoline bicyclic ring; and the enamine derivatives thereof.

Abstract: An intermediate represented by the following formula, for synthesizing --3-hydroxy-3-cephem compounds. ##STR1## wherein A and B each is a hydrogen or amino substituent; R is a hydrogen or thiol substituent; Hal is a halogen; X is a hydroxy or carboxy protecting group; the broken line between A and R shows that when R and B are hydrogens, and A is a carboxylic acyl, the substituents can be combined to form an azetidinothiazoline bicyclic ring; and the enamine derivatives thereof.

Abstract: Azetidine derivatives of the formula: ##STR1## wherein A is amino or substituted amino; COB is carboxy or protected carboxy; R.sup.1 is .dbd.C(CH.sub.3).sub.2, ##STR2## (R.sup.4 is alkyl, aryl or aralkyl); OR.sup.2 and OR.sup.3 independently or taken together with each other represent a ketal; Y is hydrogen or methoxy; Z is hydrogen or halogen, and a process for preparation thereof. Used as intermediates in the preparation of potent antimicrobials 1-oxadethiacephalosporins.

Abstract: Useful intermediates for preparing a 1-dethia-1-oxacephalosporin and represented by the following formula: ##STR1## (wherein R is a monovalent group resulting from the elimination of the carbonyl function of an acyl group derived from a carboxylic or carbonic acid;COB is carboxy or protected carboxy; andX is hydrogen or a nucleophilic group)are prepared from the corresponding penicillin 1-oxides of the following formula: ##STR2## (wherein R, COB, and X are as defined above) by heating, if required in the presence of a desulfurizing reagent, or by exchanging the X group with another one under the condition of an appropriate nucleophilic substitution.

Abstract: Useful intermediates for preparing a 1-dethia-1-oxacephalosporin and represented by the following formula: ##STR1## (wherein R is a monovalent group resulting from the elimination of the carbonyl function of an acyl group derived from a carboxylic or carbonic acid;COB is carboxy or protected carboxy; andX is hydrogen or a nucleophilic group)are prepared from the corresponding penicillin 1-oxides of the following formula: ##STR2## (wherein R, COB, and X are as defined above) by heating, if required in the presence of a desulfurizing reagent, or by exchanging the X group with another one under the condition of an appropriate nucleophilic substitution.

Abstract: .alpha.-[3(R)-Substituted amino-4(R)-substituted alkoxy-2-oxo-azetidin-1-yl]-.alpha.-isopropenylacetate (Ia) and .alpha.-[3(R)-substituted amino-4(R)-substituted alkoxy-2-oxo-azetidin-1-yl]-.alpha.-isopropylideneacetate (Ib) prepared from (1R,5S)-.alpha.-(3-substituted-7-oxo-4-oxa-2,6-diazabicyclo[3.2.0]hept-2-e n-6-yl)-.alpha.-isopropenylacetate or (1R,5S)-.alpha.-(3-substituted-7-oxo-4-oxa-2,6-diazabicyclo-[3.2.0]hept-2- en-6-yl)-.alpha.-isopropylideneacetate with a primary alcohol in the presence of an acid. The products are useful intermediates for preparing oxadethiacephalosporins.

Abstract: Antibacterial 7-substituted aminoacetamido oxadethiacephalosporins of the formula: ##STR1## [wherein R is substituted amino, substituted phenyl, or 5- or 6-membered hetero ring; Ar is aryl; Y is hydrogen or methoxy; Het is 5- or 6-membered aromatic hetero ring; and Z is hydroxy or carboxy protecting group] preparable e.g. by acylation of 7.alpha.-methoxy-7.beta.-amino-3-heterocyclic thiomethyl-3-cephem-4-carboxylic acid derivatives, are highly active against gram-positive and gram-negative bacteria, especially those resistant to other cephalosporins and penicillins.

Abstract: A process for preparing free carboxylic acids which comprises treating an optionally substituted benzyl ester with a Lewis acid, preferably in the presence of a cation acceptor, followed by hydrolysis, if required.

Abstract: Useful intermediates for preparing a 1-dethia-1-oxacephalosporin and represented by the following formula: ##STR1## (wherein R is a monovalent group resulting from the elimination of the carbonyl function of an acyl group derived from a carboxylic or carbonic acid;COB is carboxy or protected carboxy; andX is hydrogen or a nucleophilic group)are prepared from the corresponding penicillin 1-oxides of the following formula: ##STR2## (wherein R, COB, and X are as defined above) by heating, if required in the presence of the desulfurizing reagent, or by exchanging the X group with another one under the condition of an appropriate nucleophilic substitution.