18549-40-1Relevant articles and documents
Polymer-supported ferric chloride as a heterogeneous catalyst for chemoselective deprotection of acetonides
Chari, M. Adharvana,Syamasundar
, p. 708 - 710 (2005)
Acetonides undergo chemoselective deprotection to afford the corresponding 1,2-diols in excellent yields using polymer (PVP)-supported ferric chloride as a heterogeneous catalyst in acetonitrile-dichloromethane at room temperature.
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Seebeck et al.
, p. 1142,1145 (1944)
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Removal of O-benzyl protecting-groups of carbohydrate derivatives by catalytic, transfer hydrogenation
Rao, Vanga S.,Perlin, Arthur S.
, p. 175 - 177 (1980)
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Williams,Loewus
, p. 149,150-155 (1978)
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Quantification of deuterium isotopomers of tree-ring cellulose using nuclear magnetic resonance
Betson, Tatiana R.,Augusti, Angela,Schleucher, Juergen
, p. 8406 - 8411 (2006)
Stable isotopes in tree rings are important tools for reconstruction of past climate. Deuterium (D) is of particular interest since it may contain climate signals and report on tree physiology. Measurements of the D/H ratio of tree-ring cellulose have proven difficult to interpret, presumably because the D/H ratio of the whole molecule blends the abundances of the seven D isotopomers of cellulose. Here we present a method to measure the abundance of the D isotopomers of tree-ring cellulose by nuclear magnetic resonance spectroscopy (NMR). The method transforms tree-ring cellulose into a glucose derivative that gives highly resolved, quantifiable deuterium NMR spectra. General guidelines for measurement of D isotopomers by NMR are described. The transformation was optimized for yield and did not alter the original D isotopomer abundances, thus, conserving the original signals recorded in wood cellulose. In the tree-ring samples tested, the abundances of D isotopomers varied by approximately ±10% (2% standard error). This large variability can only be caused by biochemistry processes and shows that more information is present in D isotopomer abundances, compared to the D/H ratio. Therefore, measurements of the D isotopomer distribution of tree rings may be used to obtain information on long-term adaptations to environmental changes and past climate change.
INTERACTION BETWEEN ACETONE AND SOME CARBOHYDRATE BENZENEBORONATES: SELECTIVE ACETONOLYSIS OF 2-PHENYL-1,3,2-DIOXABOROLANES
Griffiths, Chridtopher J.,Weigel, Helmut
, p. 17 - 22 (1980)
Treatment of D-glucitol 1,3:2,4:5,6-tris(benzeneboronate), D-mannitol 1,2:3,4:5,6-tris(benzeneboronate), and α-D-glucofuranose 1,2:3,5-bis(benzeneboronate) with acidified acetone, followed by chromatography using lyotropic solvents, gives 5,6-O-isopropylidene-D-glucitol, 1,2-O-isopropylidene-D-mannitol, and 1,2-O-isopropylidene-α-D-glucofuranose, respectively, in yields of 43-78percent.
A Warburg effect targeting vector designed to increase the uptake of compounds by cancer cells demonstrates glucose and hypoxia dependent uptake
Glenister, Alexandra,Simone, Michela I.,Hambley, Trevor W.
, (2019)
Glycoconjugation to target the Warburg effect provides the potential to enhance selective uptake of anticancer or imaging agents by cancer cells. A Warburg effect targeting group, rationally designed to facilitate uptake by glucose transporters and promote cellular accumulation due to phosphorylation by hexokinase (HK), has been synthesised. This targeting group, the C2 modified glucose analogue 2-(2-[2-(2-aminoethoxy)ethoxy]ethoxy)-D-glu-cose, has been conjugated to the fluorophore nitrobenzoxadiazole to evaluate its effect on uptake and accumulation in cancer cells. The targeting vector has demonstrated inhibition of glucose phosphorylation by HK, indicating its interaction with the enzyme and thereby confirming the potential to facilitate an intracellular trapping mechanism for compounds it is conjugated with. The cellular uptake of the fluorescent analogue is dependent on the glucose concentration and is so to a greater extent than is that of the widely used fluorescent glucose analogue, 2-NBDG. It also demonstrates selective uptake in the hypoxic regions of 3D spheroid tumour models whereas 2-NBDG is distributed primarily through the normoxic regions of the spheroid. The increased selectivity is consistent with the blocking of alternative uptake pathways.
Acetalation studies. Part IX. Reaction of sucrose and some related sugars with acetone in the presence of iodine; a novel cleavage-isopropylidenation method
Verhart, Cor G. J.,Caris, Brigitte M. G.,Zwanenburg, Binne,Chittenden, Gordon J. F.
, p. 348 - 352 (1992)
An efficient cleavage-isopropylidenation reaction of sucrose, catalyzed by iodine, is described.Related D-fructofuranosyl-containing oligosaccharides and their individual monosaccharide units were treated in a similar manner to yield isopropylidenated monosaccharide derivatives.The reaction conditions are particularly mild and selective.Some mechanistic aspects of the procedure are also discussed.
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Kiso,Hasegawa
, p. 95,96-101 (1976)
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Nascent-HBr-Catalyzed Removal of Orthogonal Protecting Groups in Aqueous Surfactants
Bera, Smritilekha,Gupta, Shilpi,Mondal, Dhananjoy
, (2020/02/04)
Organic reactions in the aqueous environment have recently emerged as a promising research area. The generation of nascent-HBr from the slow hydrolysis of the dispersed catalyst, benzyl bromide, with the interior water present in the hydrophobic core of the confined micellar medium in aqueous surfactant is described for the first time. The sustained-release nascent-HBr enabled the chemoselective cleavages of acid-sensitive orthogonal functionalities present in carbohydrates, amino alcohols, and hydroxylated acyclic compounds in good to excellent yields.