Abstract: The compound 2-deoxy-2,2-difluoro-D-erythro-pentofuranos-1-ulose-3,5-dibenzoate is described and claimed.

Abstract: A stereoselective glycosylation process for preparing beta-anomer enriched 2'-deoxy-2',2'-difluoropurine and triazole nucleosides and 2'-deoxy-2'-fluoropurine and triazole nucleosides which involves reacting an alpha-anomer enriched 2-deoxy-2,2-difluorocarbohydrate or 2-deoxy-2-fluorocarbohydrate with at least a molar equivalent of a nucleobase derivative in a low freezing inert solvent.

Abstract: A stereoselective anion glycosylation process for preparing beta- and alpha-anomer enriched 2', 2'-difluoro-2'-deoxynucleosides and 2'-deoxy-2'-fluoronucleosides by reacting an alpha- or beta-anomer enriched 2-deoxy-2-fluorocarbohydrate or 2-deoxy-2,2-difluorocarbohydrate with at least a molar equivalent of a salt of a nucleobase derivative in an inert solvent.

Abstract: A stereoselective glycosylation process for preparing beta-anomer enriched 2'-deoxy-2',2'-difluoropyrimidine nucleosides and 2'-deoxy-2'-fluoropyrimidine nucleosides which involves reacting an alpha-anomer enriched 2-deoxy-2,2-difluorocarbohydrate or 2-deoxy-2-fluorocarbohydrate with at least a molar equivalent of a pyrimidine nucleobase derivative in a low freezing inert solvent.

Abstract: A stereoselective glycosylation process for preparing beta- and alpha-anomer enriched 2'-deoxy-2',2'-difluoronucleosides and 2'-deoxy-2'-fluoronucleosides by reacting a concentrated alpha- or beta-anomer enriched 2 -deoxy-2,2-difluorocarbohydrate or 2-deoxy-2 -fluorocarbohydrate with at least a molar equivalent of a nucleobase derivative in a high boiling inert solvent.

Abstract: A stereoselective glycosylation process for preparing beta-anomer enriched 2'-deoxy-2',2'-difluoropyrimidine nucleosides and 2'-deoxy-2'-fluoropyrimidine nucleosides which involves reacting an alpha-anomer enriched 2-deoxy-2,2-difluorocarbohydrate or 2-deoxy-2-fluorocarbohydrate with at least a molar equivalent of a pyrimidine nucleobase derivative in a low freezing inert solvent.

Abstract: A stereoselective process for preparing an alpha-anomer enriched 1-.alpha.-halo-2-deoxy-2,2-difluoro-D-ribofuranosyl derivatives involving contacting a 3,5-hydroxy protected-2-deoxy-2,2-difluoro-D-ribofuranosyl-1-.beta.-sulfonate with a halide source in an inert solvent.

Abstract: The present invention provides a process for preparing lactone intermediates to 2',2'-difluoronucleosides whereby reversion back to the lactone's open chain precursor is minimized and the desired erythro enantiomer can be selectively isolated from an enantiomeric mixture of erythro and threo lactones in crystalline form. Also provided is a process for producing 2'-deoxy-2',2'-difluoronucleosides in about a 1:1 .alpha./.beta. anomeric ratio, and processes for selectively isolating .beta.-2'-deoxy-2',2'-difluorocytidine, or an organic or inorganic acid addition salt thereof, from the 1:1 .alpha./.beta. mixture.

Abstract: A stereoselective fusion glycosylation process for prearing beta-anomer enriched 2'-deoxy-2',2'-difluoronucleotides and 2'-deoxy-2'-fluoronucleosides by reacting an alpha-anomer enriched 2-deoxy-2,2-difluorocarbohydrate or 2-deoxy-2-fluorcarbohydrate with at least a 3 molar equivalent of a nucleobase derivative at a temperature sufficient to melt the carbohydrate and nucleobase derivative.

Abstract: A stereoselective process for preparing alpha-anomer enriched 2-deoxy-2,2-difluoro-D-ribofuranosyl sulfonates by contacting a lactol with an amine base in an inert solvent, adjusting the temperature and adding a sulfonating reagent.

Abstract: A stereoselective fusion glycosylation process for preparing beta-anomer enriched 2'-deoxy-2',2'-difluoronucleosides and 2'-deoxy-2'-fluoronucleosides is provided which requires reacting an alpha-anomer enriched 2-deoxy-2,2-difluorocarbohydrate or 2-deoxy-2-fluorocarbohydrate with at least 3 molar equivalents of a nucleobase derivative at a temperature sufficient to fuse the carbohydrate and nucleobase; in the absence of a catalyst and a solvent.

Abstract: A process for providing an alpha-anomer enriched ribofuranosyl sulfonate from a beta-anomer ribofuranosyl sulfonate; comprising treating a beta-anomer ribofuranosyl sulfonate or anomeric mixture thereof with a conjugate anion of a sulfonic acid source at elevated temperatures in an inert solvent.

Abstract: A process for separating an anomeric mixture of alpha and beta 2-deoxy-2,2-difluoro-D-ribofuranosyl-1-alkylsulfonates by contacting the anomeric mixture with a solvent; heating; adding a countersolvent; and lowering the temperature.

Abstract: A stereoselective process for preparing 2-deoxy-2,2-difluoro-D-ribofuranosyl beta-anomer enriched aryl sulfonates or substituted arylsulfonates involving reacting a lactol with an acid scavenger and a sulfonating reagent in an inert solvent.

Abstract: The present invention provides a process for preparing lactone intermediates to 2',2'-difluoronucleosides whereby reversion back to the lactone's open chain precursor is minimized and the desired erythro enantiomer can be selectively isolated from an enantiomeric mixture of erythro and threo lactones in crystalline form. Also provided is a process for producing 2'-deoxy-2',2'-difluoronucleosides in about a 1:1 .alpha./.beta. anomeric ratio, and processes for selectively isolating .beta.-2'-deoxy-2',2'-difluorocytidine, or an organic or inorganic acid addition salt thereof, from the 1:1 .alpha./.beta. mixture.

Abstract: The present invention provides a process for preparing lactone intermediates to 2',2'-difluoronucleosides whereby reversion back to the lactone's open chain precursor is minimized and the desired erythro enantiomer can be selectively isolated from an enantiomeric mixture of erythro and threo lactones in crystalline form. Also provided is a process for producing 2'-deoxy-2',2'-difluoronucleosides in about a 1:1 .alpha./.beta. anomeric ratio, and processes for selectively isolating .beta.-2'-deoxy-2',2'-difluorocytidine, or an organic or inorganic acid addition salt thereof, from the 1:1 .alpha./.beta. mixture.

Abstract: 7-Amino-3-pyridiniummethyl (and substituted pyridiniummethyl)-3-cephem-4-carboxylic acid hydrothiocyanate salts and a process for the preparation thereof are provided. The salts are useful for recovering the pyridinium nuclei from reaction mixtures in which they are formed or used.

Abstract: Ceftazidime pentahydrate in crystalline form is provided in a one-step process comprising acidic removal of protecting groups from an amino-protected and carboxy-protected ceftazidime, separation of aqueous phase after addition of a water-immiscible organic solvent, and precipitation of pentahydrate by adjusting pH of aqueous phase from about 3.5 to about 4.5.

Abstract: Ceftazidime bishydrobromide crystalline monohydrates are provided and are useful for preparing crystalline ceftazidime pentahydrate.

Abstract: (6R,7R)-7-[(Z)-2-(2-triphenylmethylaminothiazol-4-yl)-2-(2-tert.-butoxycarb onylprop-2-oxyimino)acetamido]-3-(1-pyridiniummethyl)ceph-3-em-4-carboxylat e is isolated by formation of N,N-dimethylacetamide solvates.