title: Synthesis of a spacer-linked derivative of heptopyranosyl(α1-3)heptopyranose expressed in lipooligosaccharide and lipopolysaccharide.
abstract: Glycosylation of penta-O-acetyl heptopyranosyl trichloroacetimidate with the 3-OH acceptor, methyl 2-O-benzyl-4,6-O-benzylidene-7,8-dideoxy-α-D-manno-oct-7-enopyranoside, gave the desired α1-3-linked disaccharide in a 94% yield. The oct-enopyranoside moiety of the disaccharide was converted to the heptoside by oxidative cleavage with osmium tetroxide/NaIO(4) and subsequent reduction with NaBH(4). The resulting α1-3-linked heptose disaccharide was converted to a tricholoroacetaimidate derivative containing a benzoyl group at C-2. This donor was glycosylated with 2-(carbobenzoxyamino)-1-ethanol to give an α spacer-linked disaccharide derivative in a 90% yield. Zemplén deacylation of the derivative and subsequent hydrogenolysis gave a 2-aminoethyl glycoside of heptopyranosyl(α1-3)heptopyranose.
authors.affiliation: Department of Life and Food Sciences, Tottori University, Tottori, Japan. yamasaki@muses.tottori-u.ac.jp
authors.forename: Ryohei
authors.initials: R
authors.lastname: Yamasaki
authors.forename: Kaori
authors.initials: K
authors.lastname: Nagahara
authors.forename: Katsuya
authors.initials: K
authors.lastname: Kishimoto
authors.forename: Akihiko
authors.initials: A
authors.lastname: Takajyo
mesh_terms: D001894:Borohydrides / Q000737:chemistry; D004187:Disaccharides / Q000138:chemical synthesis*; D006031:Glycosylation; D008070:Lipopolysaccharides / Q000737:chemistry*; D009993:Osmium Tetroxide / Q000737:chemistry; D010084:Oxidation-Reduction; D010504:Periodic Acid / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001894:Borohydrides; D004187:Disaccharides; D008070:Lipopolysaccharides; C023023:lipid-linked oligosaccharides; D010504:Periodic Acid; C025364:sodium borohydride; C009288:metaperiodate; D009993:Osmium Tetroxide