14040-20-1Relevant articles and documents
Syntheses of model oligosaccharides of biological significance. XII. Synthesis, NMR, and conformational analysis of trideuteriomethyl 4-O-(β-D-mannopyranosyl)-2-acetamido-2-deoxy-β-D-glucopyranoside: the use of DEPT 1H to 13C transfer for T1 measurements and NOE assignments of ...
Lee, Ho Huat,Congson, Ligaya N.,Whitfield, Dennis M.,Radics, Lajos R.,Krepinsky, Jiri J.
, p. 2607 - 2617 (2007/10/02)
The title disaccharide Manp(β1-4)GlcpNAcβ1-OCD3 has been prepared by a short synthetic sequence through the inversion of configuration from gluco to manno involving benzyl Glcp(β1-4)GlcpNAc.The disaccharide was subjected to detailed high-field 1H and 13C NMR study.First, conventional and 2D spectra were run to afford a complete set of assigned spectral parameters.Next, steady-state 1H- NOE and 1H, 13C spin lattice relaxation experiments were performed to infer dynamic spectral data related to molecular conformation.Owing to tight couplings and signal overlaps in the 1H spectrum, proton relaxation and selected NOE data were obtained via 13C NMR after transfer of the actual, non-equilibrium, proton magnetization to the 13C frequency domain.Using this experimental approach it has been found that T1's for Manp H-4 and GlcpNAc H-2 were substantially longer than those of the other sugar ring protons, and that the principal interresidue dipolar contact in Manp(β1-4)GlcpNAcβ1-OCD3 takes place between Manp H-1 and GlcpNAc H-4.Subsequently, a conformational analysis of the disaccharide was executed by means of a semiempirical method comparing Boltzman-averaged computed observables with experimental T1 and NOE values.The results suggest that the disaccharide has substantial conformational flexibility.Its exo-anomeric-stabilized conformational minimum at approximately Φ = +50 deg (Ψ = 0 +/- 10 deg) of the glycosidic rotational angle is significantly populated but this global minimum does not represent the only rotational form available to the molecule.
N-Allyl and N-benzyl derivatives of 2-amino-2-deoxy-D-glucose
Gigg, Roy,Conant, Robert
, p. C5 - C9 (2007/10/02)
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The synthesis of 2-acetamido-2-deoxy-4-O-beta-D-mannopyranosyl-D-glucose.
Shaban,Jeanloz
, p. 115 - 127 (2007/10/10)
Condensation of 4,6-di-O-acetyl-2,3-O-carbonyl-alpha-D-mannopyranosyl bromide with 2-amino-2-N,3-O-carbonyl-5.6-O-isopropylidene-D-glucose diethyl acetal gave, unexpectedly, 2-amino-2-N,3-O-carbonyl-2-deoxy-4-O-(4,6-di-O-acetyl-2,3-O-carbonyl-alpha-D-mannopyranosyl)-5,6-O-isopropylidene-D-glucose diethyl acetal, futher transformed, by de-esterification followed by acetylation, into the previously known 2-amino-2-N,3-O-carbonyl-2-deoxy-5,6-O-isopropylidene-4-O-alpha-D-mannopyranosyl-D-glucose diethyl acetal and its tetra-O-acetyl derivative. Benzyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-beta-D-glucopyranoside was condensed with 2-O-acetyl-3,4,6-tri-O-benzyl-beta-D-glucopyranosyl bromide to give benzyl 2-acetamido-4-O-(2-O-acetyl-3,4,6-tri-O-benzyl-beta-D-glucopyranosyl)-3,6-di-O-benzyl-2-deoxy-beta-D-glucopyranoside. Removal of the 2-O-acetyl group, followed by oxidation with acetic anhydridedimethyl sulfoxide, gave a beta-D-arabino-hexosid-2-ulose (25). After reduction with sodium borohydride, removal of the benzyl groups gave crystalline 2-acetamido-2-deoxy-4-O-beta-D-mannopyranosyl-D-glucose (27). The anomeric configuration of the glycosidic linkage was ascertained by comparison with the alpha-D-linked disaccharide.
