- Toward a Molecular Lego Approach for the Diversity-Oriented Synthesis of Cyclodextrin Analogues Designed as Scaffolds for Multivalent Systems
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A modular strategy has been developed to access a diversity of cyclic and acyclic oligosaccharide analogues designed as prefunctionalized scaffolds for the synthesis of multivalent ligands. This convergent approach is based on bifunctional sugar building
- Lepage, Mathieu L.,Schneider, Jérémy P.,Bodlenner, Anne,Compain, Philippe
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- Stereoselective synthesis of α-glycosyl azides by TMSOTf-mediated ring opening of 1,6-anhydro sugars
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Access to α-glycosyl azides in modest to high diastereoselectivity by way of TMSN3 ring-opening of 1,6-anhydro sugars mediated by TMSOTf is reported. The reaction tolerates a wide variety of functional groups including alcohol, alkyne, azide and ester groups. The efficient synthesis of a pseudopentasaccharide in five steps from commercially available levoglucosan by way of a "click-click" approach is presented to highlight the interest of the TMSN3 ring-opening reaction. A new route to α-glycosyl azides by way of TMSN3 ring-opening of 1,6-anhydro sugars is presented. The potential of this methodology is demonstrated by the expeditious synthesis of a pseudopentasaccharide following a "click-click" approach.
- Lepage, Mathieu L.,Bodlenner, Anne,Compain, Philippe
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p. 1963 - 1972
(2013/05/21)
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- EFFECT OF PROTECTING GROUPS AND SOLVENTS IN ANOMERIC O-ALKYLATION OF MANNOPYRANOSE
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Anomeric O-alkylation of mannopyranoses with various protecting groups was investigated using mannose derivatives and 2,3-O-isopropylidene-1-O-trifluoromethanesulfonyl-D-glycerol (1) as alkylating agent.Generally, in polar solvents higher α/β ratios were obtained than in nonpolar solvents.Sterically demanding protecting groups at the 6-O-position and polar solvents led to higher yields.Reactivity differences were explained by different complex formation.Based on these results mannopyranosyl-α(1-4)glucopyranosides 26 and 27 were synthesized using mannose derivatives 5 and 6 having a 6-O-(p-methoxyphenyl)diphenylmethyl group and galactosyl trifluoromethanesulfonate 24 or nonafluorobutanesulfonate (nonaflate) 25, respectively, as alkylating agents.
- Tamura, Junichi,Schmidt, R. R.
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p. 895 - 912
(2007/10/02)
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- Anomeric O-Alkylation, 9. Disaccharide Synthesis via Anomeric O-Alkylation
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Base-promoted reaction of tetra-O-benzyl-glucose 1a with secondary alkyl trifluoromethanesulfonates 2 and 3 in toluene provides in the presence of 15-crown-5 preferentially β-glycosides 2aβ and 3aβ, respectively, in high yields.For reactions carried out a
- Tsvetkov, Yury E.,Klotz, Wolfgang,Schmidt, Richard R.
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p. 371 - 376
(2007/10/02)
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- The Substrate Specificity of the Enzyme Amyloglucosidase (AMG). Part II. 6-Substituted Maltose Derivatives
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The synthesis of maltose derivatives substituted in the 6-position with F, I, N3, NH2, NHAc, COOH or COOMe, and having a 5-6 double bond, are described together with the preparation of the known 6-Cl and 6-Br derivatives using improved synthetic procedures.Furthermore, the 6'-Br and -F derivatives have been prepared.The identities of the deprotected methyl glycosides have in all cases been established by 1H and 13 C NMR spectroscopy.The synthetic compounds have been tested as substrates for the enzyme amyloglucosidase (AMG) and has been found that compounds with a charged group in the 6-position, such as amino or carboxylate, or with substituents in the 6'-position are not substrates for the enzyme; all the other compounds can be hydrolysed by the enzyme, although at widely differing rates.The 6-halo compounds proved in competition experiments to be potent enzyme inhibitors.
- Bock, Klaus,Pedersen, Henric
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- TOTAL SYNTHESIS OF CYCLOMALTOHEXAOSE
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Described for the first time is a total synthesis of cyclomaltohexaose, in 0.3percent overall yield, in 21 steps starting from maltose.Maltose was transformed into allyl O-(2,3,6-tri-O-benzyl-α-D-glucopyranosyl)-(1->4)-2,3,6-tri-O-benzyl-β-D-glucopyranosi
- Takahashi, Yukio,Ogawa, Tomoya
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p. 277 - 296
(2007/10/02)
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