title: Synthesis of 3-(alpha- and beta-D-arabinofuranosyl)-6-chloro-1,2,4-triazolo[4,3-b]pyridazine.
abstract: Di-O-isopropylidene- and O-methanesulfonyl-protected 1-C-(6-chloro-1,2,4-triazolo[4,3-b]pyridazin-3-yl)pentitols were prepared in three to four steps from D-galactose, D-glucose, D-mannose, and 2,3:5,6-di-O-isopropylidene-alpha-D-mannofuranose. Acid-catalysed treatment of (1S)- and (1R)-1-C-(6-chloro-1,2,4-triazolo[4,3-b]-pyridazin-3-yl)-2,3:4,5-di-O-isopropylidene-1-O-methanesulfonyl-D-arabinitols in refluxing 1,2-dimethoxyethane furnished 3-(alpha- and beta-D-arabinofuranosyl)-6-chloro-1,2,4-triazolo[4,3-b]pyridazine, respectively. Several structures, including the structure of the 3-(beta-D-arabinofuranosyl)-6-chloro-1,2,4-triazolo[4,3-b]pyridazine, were also determined by single-crystal X-ray diffraction analysis.
mesh_terms: D001089:Arabinose / Q000031:analogs & derivatives / Q000138:chemical synthesis; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D018360:Crystallography, X-Ray; D015394:Molecular Structure; D009705:Nucleosides / Q000737:chemistry*; D011724:Pyridazines / Q000138:chemical synthesis; D013237:Stereoisomerism
chemical_list: C487417:3-arabinofuranosyl-6-chloro-1,2,4-triazolo(4,3-b)pyridazine; D009705:Nucleosides; D011724:Pyridazines; D001089:Arabinose