摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
(6R,7R)-7-[(Z)-2-(2-triphenylmethylaminothiazol-4-yl)-2-(2-tert.-butoxycarbonylprop-2-oxyimino)acetamido]-3-(1-pyridiniummethyl)ceph-3-em-4-carboxylate is isolated by formation of N,N-dimethylacetamide solvates.
摘要:
N-chlorophthalimide, N-chlorosuccinimide, and N-chloroglutarimide are prepared by contacting the corresponding imide with molecular chlorine under substantially non-aqueous conditions in an inert organic solvent in the presence of a poly(4-vinylpyridine)-divinylbenzene copolymer.
摘要:
Process for 3-exomethylenecepham sulfoxides comprising reacting a 2-chlorosulfinylazetidin-4-one ester with stannic chloride in the presence of oxo compounds, for example lower alkyl ethers and lower alkyl ketones, to form a stannic chloride complex with 2-chlorosulfinylazetidinone stabilized with said oxo compounds which, upon treatment with an hydroxy-containing compound such as methyl alcohol, decomposes providing said 3-exomethylenecepham sulfoxide.
摘要:
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.
摘要:
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.
摘要:
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.