6154-71-8Relevant academic research and scientific papers
Synthesis of α- and β-linked tyvelose epitopes of the Trichinella spiralis glycan: 2-Acetamido-2-deoxy-3-O-(3,6-dideoxy-D- arabinohexopyranosyl)-β-D-galactopyranosides
Probert, Mark A.,Zhang, Jian,Bundle, David R.
, p. 149 - 170 (2007/10/03)
The anomeric configuration of tyvelose, 3,6-dideoxy-D-arabino-hexopyranose, in the recently discovered glycan epitopes of the parasite Trichinella spiralis has not been established. Two 2-(trimethylsilyl)ethyl disaccharide glycosides, α- and β-Tyv-(1 → 3)-β-D-GalNAc (4 and 5) have been synthesized to provide model compounds that, together with the methyl 3,6-dideoxy-α-and β-D-arabino-hexopyranosides (2 and 3), aid the determination of the anomeric configuration of tyvelose residues in the parasite glycan, either indirectly by immunochemical inhibition data or directly by the technique of 1H NMR spectroscopy. Methyl 3,6-dideoxy-β-D-arabinohexopyranoside (3) was synthesized from methyl 2,3-anhydro-4,6-O-benzylidene-β-D- mannopyranoside (9) by a method previously used for the α anomer 2. Benzylation of 2 provided a route to the glycosyl donor, 2,4-di-O-benzyl-3,6-dideoxy-α- D-arabino -hexopyranosyl chloride (30), that reacted with the selectively protected 2-acetamido-2-deoxy-D-galactopyranoside alcohol 18 in the presence of an insoluble silver zeolite catalyst to give the α- and β-linked disaccharides 31 and 32. Glycosylation of the related 2-acetamido-2-deoxy-D-galactopyranoside alcohol 27 by 30 under similar conditions provided disaccharides 33 and 34 containing a tether. Deprotection of the saccharide and derivatization of the tether with 1,2-diaminoethane provided amide derivatives 35 and 36 suitable for the preparation of neoglycoconjugate antigens. Complete 1H and 13C NMR chemical shifts of the deprotected disaccharides and monosaccharides are reported.
Conformation of methyl 3,4-dideoxy-α-D-arabino-hexopyranoside, the immunodominant sugar of Salmonella serogroup D1: crystal structure, 1H nmr analysis, and semi-empirical calculations
Birnbaum, George I.,Bundle, David R.
, p. 739 - 744 (2007/10/02)
Methyl 3,6-dideoxy-α-D-arabino-hexopyranoside (methyl tyveloside) crystallizes in the orthorhombic space group P212121 and the cell dimensions are a=7.478(1), b=7.933(1), c=14.064(1) Angstroem.X-ray intensity data were measured with a diffractometer and the structure was solved by direct methods.Least-squares refinement, which included all hydrogen atoms, converged at R=0.038.The pyranose ring exists as an almost perfect 4C1 chair and the conformation adopted by the glycosidic methyl group is an agreement with the requirements of the exo-anomeric effect.Both acetal oxygen atoms act as hydrogen-bond acceptors, and the H...O bond distances are in agreement with this feature.The 1H nmr spectrum shows that the conformation of the pyranose ring in aqueous solution is indistinguisable from that in the crystal.The minimum energy conformation of a pentasaccharide fragmentof a Salmonella O-antigen, calculated with tyvelose coordinates obtained by bond modification, is in good agreement with the conformation which was calculated with tyvelose coordinates obtained from the X-ray analysis.
The Reaction of Methyl 4,6-O-Isopropylidene-2,3-O-thiocarbonyl-α-D-mannoside with Methyl Iodide: a Synthesis of Methyl α-Tyveloside (Methyl 3,6-Dideoxy-α-D-arabino-hexopyranoside)
Patroni, Joseph J.,Skelton, Brian W.,Stick, Robert V.,White, Allan H.
, p. 987 - 999 (2007/10/02)
The reaction of methyl 4,6-O-isopropylidene-2,3-O-thiocarbonyl-α-D-mannoside with methyl iodide gives two major products, methyl 3,6-dideoxy-3,6-diiodo-2-O-(methylthio)carbonyl-α-D-altropyranoside and methyl 2,3-O-carbonyl-6-deoxy-6-iodo-α-D-mannopyranoside, both of which lack the 4,6-O-isopropylidene grouping but contain the 6-deoxy-6-iodo function, and another minor product.One of the major product, methyl 3,6-dideoxy-3,6-diiodo-2-O-(methylthio)carbonyl-α-D-altropyranoside, is convertedinto methyl α-tyveloside by sequential reduction and ester removal.The incorporation of iodine at C 6 is seemingly due to hydrogen iodide, and may be suppressed in the presence of N,N,N,N-trtramethylnaphthalene-1,8-diamine or propylene oxide, or by the use of 4,6-O-benzylidene-2,3-O-thiocarbonyl-α-D-mannoside as substrate.Methyl iodide/propylene oxide is apparently an efficient combination for thiocarbonate (C=S) into carbonate conversion.The structure of the minor product was shown by single-crystal X-ray diffraction to be 1,6-anhydro-3-deoxy-3-iodo-2-O-(methylthio)carbonyl-β-D-altropyranose.
