- Selective and Scalable Synthesis of Sugar Alcohols by Homogeneous Asymmetric Hydrogenation of Unprotected Ketoses
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Sugar alcohols are of great importance for the food industry and are promising building blocks for bio-based polymers. Industrially, they are produced by heterogeneous hydrogenation of sugars with H2, usually with none to low stereoselectivities. Now, we present a homogeneous system based on commercially available components, which not only increases the overall yield, but also allows a wide range of unprotected ketoses to be diastereoselectively hydrogenated. Furthermore, the system is reliable on a multi-gram scale allowing sugar alcohols to be isolated in large quantities at high atom economy.
- Tindall, Daniel J.,Mader, Steffen,Kindler, Alois,Rominger, Frank,Hashmi, A. Stephen K.,Schaub, Thomas
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supporting information
p. 721 - 725
(2020/10/19)
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- Enumeration of hydroxyl groups of sugars and sugar alcohols by aqueous-based acetylation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry
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RATIONALE The properties of carbohydrates are determined in part by the number and stereochemical arrangement of their hydroxyl groups. To facilitate their analysis, rapid methods are needed to identify and enumerate hydroxyl groups in sugars and polyalcohols, especially methods that are water-based. METHODS The present report details the results of an alternative method for identification and enumeration of hydroxyl groups in aqueous media. It employs vinyl acetate to selectively derivatize hydroxyl groups in analytes, followed by analysis of the reaction mixtures by matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry (MALDI-TOF-MS). RESULTS The method has been applied to several single and multi-component mixtures of monosaccharides and polyalcohols. The O-acetylated products were analyzed without chromatographic separation or purification by MALDI-TOF-MS. The mass spectra revealed consecutive ion peaks that are separated by 42 mass units as a consequence of displacement of one hydroxyl hydrogen by one acetyl group. CONCLUSIONS A rapid and aqueous-based method is described to enumerate the hydroxyl groups in carbohydrates. The number of ion peaks due to derivatized products is determined by MALDI-TOF-MS, and corresponds to the number of free hydroxyl groups in the analyte. The method is applicable to both single and multi-component mixtures. Published 2011. This article is a US Government work and is in the public domain in the USA. Published 2012. This article is a US Government work and is in the public domain in the USA.
- Adeuya, Anthony,Price, Neil P.J.
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experimental part
p. 1372 - 1376
(2012/08/08)
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- A Definitive Synthesis of D-myo-Inositol 1,4,5,6-Tetrakisphosphate and Its Enantiomer D-myo-Inositol 3,4,5,6-Tetrakisphosphate from a Novel Butane-2,3-diacetal-Protected Inositol
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New and rapid syntheses of the enantiomeric intracellular signalling molecules D-myo-inositol 1,4,5,6-tetrakisphosphate (1a) and D-myo-inositol 3,4,5,6-tetrakisphosphate (1b) are described. The synthetic strategy employs the novel butane-2,3-diacetal-prot
- Mills, Stephen J.,Riley, Andrew M.,Liu, Changsheng,Mahon, Mary F.,Potter, Barry V. L.
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p. 6207 - 6214
(2007/10/03)
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- Impact of the central hydroxyl groups on the activity of symmetrical HIV-1 protease inhibitors derived from L-mannaric acid
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The influence of the central hydroxyl groups on the anti-viral activity of symmetrical HIV-1 protease inhibitors derived from L-mannaric acid has been examined. L-Iditol was synthesized and used as a chiral precursor for the synthesis of the corresponding inhibitor with inverted configuration at C-3 and C-4. Key intermediates were 3,4-O-isopropylidene-L-iditol and the activated L-idaric acid succinimidyI ester. The configurations of the central hydroxyl groups required for optimal inhibition of the HIV-1 protease were determined to be the C-3R and C-4R, i.e. the L-manno-configuration. Three C2-symmetric inhibitors were converted to their thiocarbonates and reduced to provide the corresponding hydroxyethyl transition-state mimics. Deletion of the C-4 hydroxyl group in these inhibitors gave no further improvement in the anti-viral activity. (C) 2000 Published by Elsevier Science Ltd.
- Wachtmeister, Johanna,Mühlman, Anna,Classon, Bj?rn,Kvarnstr?m, Ingemar,Hallberg, Anders,Samuelsson, Bertil
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p. 3219 - 3225
(2007/10/03)
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- Polyamides and polyesters containing 2,4:3,5-di-O-methylene-L-idaroyl residues
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Electrochemical oxidation of 2,4:3,5-di-O-methylene-D-gluconic acid in strong alkaline medium afforded a mixture of 2,4:3,5-di-O-methylene-D-glucaric acid 4 and 2,4:3,5-di-O-methylene-L-idaric acid 1 in a 1/8 ratio with a current efficiency of 53percent.Force-field calculations using Allinger's molecular mechanics program MM2p85 on 1 and 4 indicate that these cis-fused tetrahydro-dioxino-1,3-dioxin ring systems possess an O-inside conformation with a steric energy of 110.3 and 123.5 kJ*mol-1, respectively.Their conformation was confirmed by 400-MHz 1H- and 100-MHz 13C NMR measurements.A series of polycondensates were prepared by homogeneous solution polymerisation of 1 with an aromatic diol or aromatic diamine, which were analyzed by DSC and TGA.
- Tinnemans, A. H. A.,Budding, H. A.,Stein, F.,Venekamp, J. C.
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p. 181 - 186
(2007/10/02)
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- Synthesis of Optically Active Inositol Derivatives Starting from D-Glucurono-6,3-lactone
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D-Glucurono-6,3-lactone was converted to optically active and partially protected inositols.The synthetic strategy involves an efficient conversion of the D-gluco configuration to the L-ido configuration and dials to cyclitols.
- Watanabe, Yutaka,Mitani, Motohiro,Ozaki, Shoichiro
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p. 123 - 126
(2007/10/02)
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- SYNTHESIS OF L-IDARO-1,4-LACTONE, AN INHIBITOR OF α-L-IDOSID-URONASE
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L-Idaro-1,4-lactone was synthesized by two different, published methods: (1) epimerization of monopotassium D-glucarate by refluxing in aqueous barium hydroxide, and (2) oxidation of L-iditol by heating in dilute nitric acid.The lactone, formed by heat dehydration from aqueous solution at low pH, was purified by paper chromatography, and quantitated by gas-liquid chromatography using inositol as the internal standard.The monolactone inhibited human, seminal-fluid α-L-idosiduronase activity, with either phenyl or 4-methylumbelliferyl α-L-idosiduronic acid as the substrate, to the same degree as D-glucaro-1,4-lactone inhibits α-D-glucosiduranose.
- Herd, J. Kenneth,Mayberry, William R.,Snell, Robert L.
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- Synthesis of Saccharides and Related Polyhydroxylated Natural Products. 1. Simple Alditols
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A new approach to sugar synthesis is demonstrated through syntheses of tetritols, pentitols, and hexitols; titanium-catalyzed asymmetric epoxidation and a new selective opening reaction of 2,3-epoxy alcohols play essential roles.
- Katsuki, T.,Lee, A. W. M.,Ma, P.,Martin, V. S.,Masamune, S.,et al.
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p. 1373 - 1378
(2007/10/02)
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- SYNTHESIS OF 2,3,4,6-TETRA-O-BENZYL-L-IDOPYRANOSE
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A synthesis of 2,3,4,6-tetra-O-benzyl-L-idopyranose (15) is described, based on L-sorbose as the starting material.By a succession of well known, high-yielding procedures, the ketose was converted into a 2:1 mixture of 1,3,4,5-tetra-O-benzyl-2-O-(tert-but
- Helleur, Robert,Rao, Vanga S.,Perlin, Arthur S.
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