title: Stereoselective syntheses of the O,N-protected subunits of the tunicamycins.
abstract: The synthesis of the title compounds is described, i.e. coupling of the ylide, generated from the iodophosphonium salt of protected N-phthaloyl-D-galactosamine with 2,3-O-isopropylidene D-ribo-aldehyde afforded an undecose in high yield. Hydroboration-oxidation reaction of the olefinic linkage in the undecose led to the desired tunicamine, as the predominant product. After conversion of the latter to a glycosyl acceptor, this was assembled with the fully protected 2-oxyimino-2-deoxy-alpha-D-arabino-hexopyranosyl bromide, leading to a trehalose-type alpha, beta-disaccharide.
authors.affiliation: Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Karpiesiuk
authors.forename: A
authors.initials: A
authors.lastname: Banaszek
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000138:chemical synthesis*; D005688:Galactosamine / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D014199:Trehalose / Q000031:analogs & derivatives / Q000138:chemical synthesis; D014312:Trisaccharides / Q000138:chemical synthesis; D014415:Tunicamycin / Q000031:analogs & derivatives* / Q000138:chemical synthesis*
chemical_list: D004187:Disaccharides; D014312:Trisaccharides; D014415:Tunicamycin; C076322:tunicamine; D005688:Galactosamine; D014199:Trehalose