- Synthesis of Glycosyl Chlorides and Bromides by Chelation Assisted Activation of Picolinic Esters under Mild Neutral Conditions
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A general method has been developed for the formation of glycosyl chlorides and bromides from picolinic esters under mild and neutral conditions. Benchtop stable picolinic esters are activated by a copper(II) halide species to afford the corresponding products in high yields with a traceless leaving group. Rare β glycosyl chlorides are accessible via this route through neighboring group participation. Additionally, glycosyl chlorides with labile protecting groups previously not easily accessible can be prepared.
- Balzer, Paul G.,Blaszczyk, Stephanie A.,Duan, Xiyan,Ma, Zhi-Xiong,Simmons, Christopher J.,Stevens, Christopher M.,Tang, Weiping,Wang, Hao-Yuan,Wen, Peng,Ye, Wenjing,Yin, Dan
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supporting information
(2020/02/28)
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- Gram scale synthesis of A (type 2) and B (type 2) blood group tetrasaccharides through 1,6-anhydro-N-acetyl-β-D-glucosamine
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Gram scale synthesis of A (type 2) and B (type 2) tetrasaccharides in the form of 3-aminopropyl glycosides is proposed starting from 3-O-benzoyl-1,6-anhydro-N-acetylglucosamine. Its galactosylation followed by re-protection gave lactosamine derivative with single free 2′-OH group in total yield 75%. Standard fucosylation and next run of re-protection in total yield 88% gave a trisaccharide Fuc-Gal-anhydroGlcNAc with single free 3′-OH group. Its standard α-galactosylation gave protected B (type 2) tetrasaccharide. For synthesis of correspondent A tetrasaccharide seven different 2-azido-2-deoxygalactosyl (GalN3) donors were tested: 6-O-acetyl-3,4-O-isopropylidene-GalN3 thioglycoside was shown to provide the best yield (89%) and stereoselectivity (α/β = 24:1). Further 1,6-anhydro cycle opening, spacer-arming and complete deprotection resulted in the target 3-aminopropyl glycosides of A (type 2) and B (type 2) tetrasaccharides, yields 87 and 85% correspondingly.
- Tyrtysh, Tatiana V.,Korchagina, Elena Yu.,Ryzhov, Ivan M.,Bovin, Nicolai V.
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- Synthesis of new sulfonic acid-containing oligosaccharide mimetics of sialyl Lewis A
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Two trisaccharides as new sulfonic acid mimetics of the sialyl Lewis A tetrasaccharide were synthesized. The natural sialic acid residue is replaced by a C-sulfonic acid moiety attached to position C-3′ of the lactosamine unit of the mimetics. The l-fucos
- Jakab, Zsolt,Fekete, Anikó,Borbás, Anikó,Lipták, András,Antus, Sándor
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experimental part
p. 2404 - 2414
(2010/06/12)
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- From disulfide- to thioether-linked glycoproteins
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(Chemical Presented) Strengthening the bond: The introduction of a thiol tag in combination with chemoselective ligation to form a disulfide-linked bioconjugate is a selective and useful method for site-selective protein glycosylation. The phosphine-mediated desulfurization of such glycoconjugates to their reductant-resistant thioether-linked counterparts completes a convergent, site-selective synthesis of thioether-linked glycoproteins (see scheme).
- Bernardes, Goncalo J. L.,Grayson, Elizabeth J.,Thompson, Sam,Chalker, Justin M.,Errey, James C.,El Oualid, Farid,Claridge, Timothy D. W.,Davis, Benjamin G.
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supporting information; experimental part
p. 2244 - 2247
(2009/02/07)
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- Glycomimetic inhibitors of the PA-IL lectin, PA-IIL lectin or both the lectins from pseudomonas
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Compositions and methods are provided related to Pseudomonas bacteria. The compositions and methods may be used for diagnosis and therapy of medical conditions involving infection with Pseudomonas bacteria. Such infections include Pseudomonas aeruginosa i
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Page/Page column 9
(2008/06/13)
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- Synthesis and antibody-binding studies of a series of parasite fuco-oligosaccharides
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Complex multifucosylated oligosaccharides are structural elements of glycoprotein and glycolipid subsets of larval, egg, and adult stages of Schistosoma, the parasitic worms that cause schistosomiasis, a serious disease affecting more than 200 million peo
- Van Roon, Anne-Marie M.,Aguilera, Begona,Cuenca, Francisco,Van Remoortere, Alexandra,Van Der Marel, Gijsbert A.,Deelder, Andre M.,Overkleeft, Herman S.,Hokke, Cornelis H.
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p. 3553 - 3564
(2007/10/03)
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- Linkable sialyl lewis x analogs
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Disclosed herein is a class of linkable tetrasaccharide compounds that includes the amino phenyl glycoside of sialyl Lewis X (SLeX) and related analogs. These compounds have conjugatable nucleophilic groups, making them useful in preparing mult
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- Synthesis of fragments of the glycocalyx glycan of the parasite Schistosoma mansoni
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The chemical synthesis of α-L-Fucp-(1→3)-β-D-GalpNAc-(1→4)-β-D-GlcpNAc- (1→3)-α-D-GalpO(CH2)5NH2, β-D-GalpNAc-(1→4)-[α-L-Fucp-(1→3)-]β-D-GlcpNAc- (1→3)-α-D-GalpO(CH2)5NH2, and α-L-Fucp-(1→3
- Agoston, Karoly,Kerekgyarto, Janos,Hajko, Janos,Batta, Gyula,Lefeber, Dirk J.,Kamerling, Johannis P.,Vliegenthart, Johannes F. G.
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p. 151 - 161
(2007/10/03)
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- The conformational behaviour of fucosyl and carbafucosyl mimetics in the free and in the protein-bound states
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The conformational behaviours of fucosyl glycosides bearing a glyceryl aglycon and their corresponding carbafucosyl glycomimetics have been studied both in aqueous solution and when bound to a fucose-specific lectin (Aurelia Aurantia Agglutinnin), using a combination of NMR spectroscopy (J and NOE data) and molecular mechanics calculations. Analogies and differences between the mimetics and the natural compounds have been found.
- Carpintero, Mercedes,Fernandez-Mayoralas, Alfonso,Jimenez-Barbero, Jesus
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p. 681 - 689
(2007/10/03)
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- Synthesis of the Lewis b hexasaccharide and squarate acid-HSA conjugates thereof with various saccharide loadings
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The Lewis b hexasaccharide, α-Ll-Fucp-(1 → 2)-β-D-Galp-(1 → 3)-[α-L-Fucp-(1 → 4)]-β-D-GlcpNAc-(1 → 3)-β-D-Galp-(1 → 4)-β-D-Glcp, has been synthesised using a convergent synthesis. Starting from ethyl 4,6-O-benzylidene-2-deoxy-2-phthalimido-1-thio-β-D-gluc
- Chernyak, Anatoly,Oscarson, Stefan,Turek, Dominika
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p. 309 - 316
(2007/10/03)
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- Glycosyl iodides are highly efficient donors under neutral conditions
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Glycosyl iodides have been prepared and subjected to glycosylation under neutral conditions. The reactions are highly efficient, giving α glycosides even with sterically demanding glycosyl acceptors. Glucosyl iodides react with allyl alcohol slowest and require refluxing conditions. Galactosyl iodides are intermediate in reactivity, providing the allyl glycoside in 3 h at room temperature, whereas glycosylation of fucosyl iodides occurs in less than 1 h under similar conditions. The scope and limitations of the reactions were demonstrated with a variety of acceptors, including an anomeric hydroxyl group, to give trehalose analogs. β-Selective glycosylation of glucosyl iodides, in the absence of C-2 participation, could be achieved by simply changing the solvent from benzene to acetonitrile. Copyright (C) 1999 Elsevier Science Ltd.
- Hadd, Michael J.,Gervay, Jacquelyn
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- The design, synthesis, and evaluation of novel conformationally rigid analogues of sialyl Lewis(x)
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The design and synthesis of a series of analogues of sialyl Lewis(x) (1) which incorporate conformationally rigid tetralin and naphthalene ring systems (2-4) has led to novel compounds which have similar potency to 1 as inhibitors of cell adhesion. Copyright (C) 1998 Elsevier Science Ltd.
- Murphy, Paul V.,Hubbard, Rod E.,Manallack, David T.,Wills, Ruth E.,Montana, John G.,Taylor, Richard J. K.
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p. 2421 - 2439
(2007/10/03)
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- Conformational differences between Fuc(α1-3)GlcNAc and its thioglycoside analogue
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NOE measurements and molecular mechanics calculations have been performed to study the conformational behaviour of Fuc(α1-3)GlcNAc and its thioglycoside analogue in solution. Experimental data show that, in contrast with the natural O-disaccharide, which
- Aguilera, Begona,Jimenez-Barbero, Jesus,Fernandez-Mayoralas, Alfonso
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- Polymer-supported solution synthesis of oligosaccharides
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The present invention provides improved syntheses of oligosacchairdes. In accordance with preferred embodiments, anomeric specificity in such syntheses can be attained using polymer-supported liquid synthetic design with certain novel diether linkers. The present invention also provides novel strategies for capping imcompletely glycosylated hydroxyls.
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- Glycosyl Azides as Building Blocks in Convergent Syntheses of Oligomeric Lactosamine and Lewis Saccharides
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Oligosaccharides containing type 2 lactosamine repeating units, e.g. neo-lacto-octaose and trimeric Lewis derivatives, are constructed using neo-lactosamine azide building blocks.The azido group provides a favorable protection of the anomeric position which is stable to versatile protecting group manipulations and glycosylation reactions.On the other hand, glycosyl azides can be converted into glycosyl fluorides via a 1,3-dipolar cycloaddition with di-tert-butyl-acetylenedicarboxylate and subsequent treatment of the resulting N-glycosyl triazoles with hydrogen fluoride-pyridine complex.Activation of the lactosamine fluorides with Lewis acids affords the possibility to extend the oligosaccharide chain with disaccharide units.Suitable protecting group combinations within the galactose and the glucosamine portion of the lactosamine unit enable selective deprotection reactions and subsequently, chain extension or branching, e.g. to yield Lewis structures. - Keywords: glycosyl azides; glycosyl fluorides; oligosaccharide synthesis; trimeric Lewis; oligomeric lactosamines.
- Broeder, Wolfgang,Kunz, Horst
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- Synthesis of a SLex mimic: a potential E-selectin binding antagonist
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Iodonium-ion-assisted condensation of methyl 4,7,8,9-tetra-O-acetyl-N-acetyl-2-O--α-D-neuraminate (15) with hexyl 2-acetamido-6-O-benzyl-3-O-(tri-O-benzyl-α-L-fucopyranosyl)-2-deoxy-β-D-glucopyranoside (12) furnished, after de
- Heskamp, B. M.,Veeneman, G. H.,Marel, G. A. van der,Boeckel, C. A. A. van,Boom, J. H. van
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p. 398 - 402
(2007/10/03)
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- THIOGLYCOSIDES AS POTENTIAL GLYCOSYL DONORS IN ELECTROCHEMICAL GLYCOSYLATION REACTIONS. PART 2: THEIR REACTIVITY TOWARD SUGAR ALCOHOLS
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Costant potential electrolysis of the glycosyl donors p-methylphenyl 2,3,4,6-tetra-O-benzyl-1-thio-β-D-glucopyranoside (1) and p-methylphenyl 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-1-thio-β-D-glucopyranoside (4) in dry acetonitrile in the presence of va
- Balovoine, Gilbert,Berteina, Sabine,Gref, Aurore,Fischer, Jean-Claude,Lubineau, Andre
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p. 1237 - 1250
(2007/10/03)
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- Improved Synthesis of α-L-Fuc(1->4)-β-D-GlcNAc and α-L-Fuc(1->6)-β-D-GlcNAc Building Blocks: A Convergent Strategy Employing 4-O->6-O Acetyl Migration; NOE Data of the Protected α-1,4-Linked Disaccharide
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The synthesis of the two ethylthio disaccharide building blocks 10 and 17 was achieved by coupling of fucosyl bromide 9 with the acceptor alcohols 6 and 7 under in situ anomerization conditions.The selectively protected 2-deoxy-2-phthalimidoglucose derivative 7 was derived from 6 by utilizing an optimized acetyl migration reaction.The ethylthio function in disaccharides 10 and 17 was activated with bromine, and excess bromine was removed with cyclohexene.The sensitive 1,6-linkage in the disaccharide 10 proved to be stable under these activating conditions.The disaccharide bromides 11 and 18 were treated with methanol to afford after deblocking the methyl glycosides 16 and 23.Homonuclear 1H-NOE data were obtained for the protected 1,4-linked disaccharide 17 suggesting that its preferred solution conformation is rather similar to the solution conformation of the deblocked disaccharide 23 in aqueous solution as known from literature data.Key Words: Oligosaccharide synthesis / Thioglycosides / Acetyl migration / Glycosidic linkage conformation / Carbohydrates
- Peters, Thomas,Weimar, Thomas
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p. 237 - 242
(2007/10/02)
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- SYNTHETIC, CONFORMATIONAL, AND IMMUNOCHEMICAL STUDIES OF MODIFIED LEWIS b AND Y HUMAN BLOOD-GROUP DETERMINANTS TO SERVE AS PROBES FOR THE COMBINING SITE OF THE LECTIN IV OF Griffonia simplicifolia
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Synheses of the methyl glycosides of the Lewis b 2)-β-D-Gal-(1->3)4)>-β-D-GlcNAc-> and Y 2)-β-D-Gal-(1->4)3)>-β-D-GlcNAc-> human blood-group determinants and both their 6a-deoxy and N-deacetylated deriva
- Spohr, Ulrike,Lemieux, Raymond U.
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p. 211 - 238
(2007/10/02)
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- Syntheses of model oligosaccharides of biological significance. 9. Syntheses of trideuteromethyl di-3,6-O-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-β-D-galactopyranoside: the I antigen branch-point trisaccharide and related disaccharides
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The title trisaccharide, 13c, was synthesized, as well as its two component disaccharides, 10c and 11c.Four disaccharides, 3c, 4c, 5c, and 7c, were also prepared to serve as model compounds for the investigation of the 3-dimensional structure of more comp
- Whitfield, Dennis M.,Ruzicka, Caroline J.,Carver, Jeremy P.,Krepinsky, Jiri J.
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p. 693 - 703
(2007/10/02)
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- Synthesis of a tri- and a hepta-saccharide which contain alpha-L-fucopyranosyl groups and are part of the complex type of carbohydrate moiety of glycoproteins.
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Reaction of a thioglycoside with methyl trifluoromethanesulfonate (methyl triflate) in the presence of a hydroxyl compound is an efficient glycosylation method. Thus, methyl triflate-promoted condensation of ethyl 4,6-O-benzylidene-2-deoxy-2-phthalimido-1
- Loenn
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p. 105 - 113
(2007/10/02)
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- Oligosaccharides from "Standardized Intermediates". Synthesis of a Branched Tetrasaccharide Glycoside Related to the Blood Group B Determinant
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A branched tetrasaccharide glycoside (16) isomeric with the human blood group B determinant (type 1) was synthesized from "building block" derivatives of the component monosaccharides.Initially a 2-O-benzoyl-3,6-di-O-benzyl-4-O-substituted-α-D-galactopyra
- Nashed, Mina A.,Anderson, Laurens
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p. 7282 - 7286
(2007/10/02)
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