- STRUCTURAL ANALYSIS OF THE CARBOHYDRATE MOIETIES OF GLYCOPROTEINS BY REGIOSPECIFIC DEGRADATION AND LIQUID CHROMATOGRAPHY
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The reaction sequence of hydrazinolysis, nitrosation, and reduction, followed by liquid chromatography (l.c.) has been studied as a method for the routine structural analysis of theasparagine-bound oligosaccharides of glycoproteins.Glycopeptides derived from IgM and ovalbumin by proteolysis were used as test materials.The hydrazinium sulphate-catalysed hydrazinolysis was superior to the longer uncatalysed reaction, in that there was less non-specific degradation and a higher degree of N-deacetylation.The nitrosation products were reduced in situ with sodium cyanoborohydride, and the l.c. analysis required 20 min for the fractionation of oligosaccharides up to decasaccharide.The l.c. profile is characteristic of the structure of the carbohydrate unit. the analytical l.c. column may also be used to isolate oligosaccharide fractions in quantities of several hundred micrograms.
- Clark, Peter I.,Narasimhan, Sivaraman,Williams, J. Michael,Clamp, John R.
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Read Online
- Targeting of glut5 for transporter-mediated drug-delivery is contingent upon substrate hydrophilicity
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Specific link between high fructose uptake and cancer development and progression highlighted fructose transporters as potential means to achieve GLUT-mediated discrimination between normal and cancer cells. The gained expression of fructose-specific transporter GLUT5 in various cancers offers a possibility for developing cancer-specific imaging and bioactive agents. Herein, we explore the feasibility of delivering a bioactive agent through cancer-relevant fructose-specific transporter GLUT5. We employed specific targeting of GLUT5 by 2,5-anhydro-D-mannitol and investigated several drug conjugates for their ability to induce cancer-specific cytotoxicity. The proof-of-concept analysis was carried out for conjugates of chlorambucil (CLB) in GLUT5-positive breast cancer cells and normal breast cells. The cytotoxicity of conjugates was assessed over 24 h and 48 h, and significant dependence between cancer-selectivity and conjugate size was observed. The differences were found to relate to the loss of GLUT5-mediated uptake upon increased conjugate size and hydrophobicity. The findings provide information on the substrate tolerance of GLUT5 and highlight the importance of maintaining appropriate hydrophilicity for GLUT-mediated delivery.
- Nahrjou, Nazanin,Ghosh, Avik,Tanasova, Marina
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- Kinetic analyses of intramolecular dehydration of hexitols in high-temperature water
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Intramolecular dehydration of the biomass-derived hexitols D-sorbitol, D-mannitol, and galactitol was investigated. These reactions were performed in high-temperature water at 523–573 K without added acid catalyst. The rate constants for the dehydration steps in the reaction networks were determined at various reaction temperatures, and the activation energies and pre-exponential factors were calculated from Arrhenius plots. The yield of each product was estimated as a function of reaction time and temperature using the calculated rate constants and activation energies. The maximum yield of each product from the dehydration reactions was predicted over a range of reaction time and temperature, allowing the selective production of these important platform chemicals.
- Yamaguchi, Aritomo,Mimura, Naoki,Shirai, Masayuki,Sato, Osamu
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- PURE HEPTASULFATED DISACCHARIDES HAVING IMPROVED ORAL BIOAVAILABILITY
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Hypersulfated disaccharides with utility in asthma or asthma related disorders are disclosed. The heptasulfated disaccharides administered orally have comparable bioavailability to the intravenous administered dosage form.
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Paragraph 0076-0077
(2018/03/09)
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- Sugar-based novel chiral macrocycles for inclusion applications and chiral recognition
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A convergent template assisted synthesis of sugar-based chiral macrocycles has been achieved. The host-guest inclusion studies have revealed significant interactions of the synthesized macrocycle with primary over secondary ammonium salt. The chiral macrocyle also discriminates between D- and L-phenylalanine methyl ester hydrochlorides as revealed by 1H NMR spectral studies on the mixture of the host and the guest molecules.
- Singh, Ankita,Khatri, Vinod,Malhotra, Shashwat,Prasad, Ashok K.
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- New fluorinated fructose analogs as selective probes of the hexose transporter protein GLUT5
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Facilitated hexose transporters (GLUTs) mediate the transport of hexoses and other substrates across the membranes of numerous cell types, and while some are expressed ubiquitously (e.g., GLUT1), others are more tissue specific (e.g., GLUT5). These properties have been exploited for the imaging of cancer cells by the use of hexose based probes, including fluorinated hexose derivatives for use with positron emission tomography (PET). However, design of new probes has been hampered by a limited understanding of how GLUT transporters interact with their substrates at the molecular level. Two fluorinated fructose surrogates designed for uptake by the GLUT5 transporter are described here: 3-deoxy-3-fluoro-d-fructose (3-FDF) and 1-deoxy-1-fluoro-2,5-anhydromannitol (1-FDAM). Synthesis (both cold and radiolabeled) and in vitro analysis of their transport characteristics in two breast cancer cell lines (EMT-6 and MCF-7) expressing GLUT5 are detailed. Both analogues are readily taken up into both cancer cell lines, with uptake mediated primarily by GLUT5. They also have low IC50 values, indicating a high affinity for the transporter, suggesting that the uptake of these probes would be unaffected by endogenously circulating fructose. Selective uptake by GLUT5 was also demonstrated in Xenopus oocytes. Finally, these results are the first demonstration that a hexose existing predominantly in the pyranose ring structure (3-FDF) is transported by GLUT5, strongly suggesting that this transporter can handle both furanose and pyranose forms of fructose.
- Soueidan, Olivier-Mohamad,Trayner, Brendan J.,Grant, Tina N.,Henderson, Jeff R.,Wuest, Frank,West,Cheeseman, Chris I.
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supporting information
p. 6511 - 6521
(2015/06/16)
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- Chiral Pool/Henry/Enzymatic routes to acetogenin synthons
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Enantio specific and enantioselective approaches to the natural (16 R,19R)- and the unnatural (16S,19S)- THF core of the bioactive acetogenin annonacin are described which utilizes both a chiral pool synthesis and enzymatic transformations. In the antipodal (2S,5S) THF series derived from D-(+)-glucosamine, the semi-protected THF aldehyde synthon allows for two-directional synthetic elaboration through a Henry reaction with a lipid-like nitroalkane. The resulting nitroalcohol having the unnatural (2S,5S)-THF core was oxidized to the corresponding a-nitroketone using a modified Collins oxidation. The intermediate a-nitroketone has potential for the preparation of the C15-C32 core and analogues through subsequent removal of the nitro group and reduction of the carbonyl.
- Qayed, Wesam S.,Luzzio, Frederick A.
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supporting information
p. 622 - 630
(2015/11/09)
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- Sulfuric acid-catalyzed dehydration of sorbitol: Mechanistic study on preferential formation of 1,4-sorbitan
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1,4-Sorbitan is a precursor to environmentally benign surfactants, which can be produced from biomass via sorbitol. Currently, sulfuric acid-catalyzed dehydration of sorbitol is the most widely used route for industrial synthesis of 1,4-sorbitan. In this work, we have studied the mechanism of the sorbitol dehydration by sulfuric acid. Our results show that both thermodynamic and kinetic parameters play significant roles to determine the yield of 1,4-sorbitan. Sorbitol preferentially forms an adduct with sulfuric acid, thereby inhibiting the subsequent dehydration of 1,4-sorbitan to isosorbide. Furthermore, a reaction mechanism is proposed for the dehydration reaction, which involves an SN2 reaction on primary C1 of sorbitol attacked by OH of secondary C4.
- Yabushita, Mizuho,Kobayashi, Hirokazu,Shrotri, Abhijit,Hara, Kenji,Ito, Shogo,Fukuoka, Atsushi
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p. 996 - 1002
(2015/09/01)
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- Dehydration of sorbitol to isosorbide over H-beta zeolites with high Si/Al ratios
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Conversion of sorbitol to isosorbide by heterogeneous catalysts is a challenge in biorefinery. Herein, H-beta zeolites with specific Si/Al ratios uniquely give isosorbide in up to 76% yield under mild conditions. Mechanistic study has suggested that acid sites on hydrophobic internal surface are active for this reaction.
- Kobayashi, Hirokazu,Yokoyama, Haruka,Feng, Bo,Fukuoka, Atsushi
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supporting information
p. 2732 - 2735
(2015/05/27)
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- Intramolecular dehydration of mannitol in high-temperature liquid water without acid catalysts
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Intramolecular dehydration of mannitol in high-temperature liquid water without adding any hazardous acid catalysts and its kinetic analyses were carried out. The dehydration behavior of mannitol was compared with that of sorbitol. 2,5-Anhydromannitol and 1,4-anhydromannitol were major products from the mannitol monomolecular dehydration in contrast with the only major product, 1,4-anhydrosorbitol, from the sorbitol monomolecular dehydration.
- Yamaguchi, Aritomo,Sato, Osamu,Mimura, Naoki,Shirai, Masayuki
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p. 45575 - 45578
(2014/12/12)
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- Preparation of anhydroalditols from commodity carbohydrates
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A practical process for the preparation of anhydroalditols from commodity carbohydrates has been described. Reductive cleavage of the glycosidic linkage in perallylated carbohydrates with triethylsilane gave the protected anhydroalditols, which were then deallylated using a PdCl2-CuCl2-Activated Charcoal system. Valuable anhydroalditols, such as 1,5-anhydro-D-glucitol, 1,5-anhydro-D-mannitol, 2,5-anhydro-D-glucitol, 2,5-anhydro-D-mannitol and 1,4-anhydro-Dribitol, were prepared in high yields and purity from carbohydrates, such as glucose, mannose, ribose, sucrose, cellulose, starch and levan.
- Yuan, Changyou,Hollingsworth, Rawle I.
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- Isolation of anhydro sugar hexitols by selective adsorbents
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A method is disclosed for recovering anhydrosugar alcohols from a mixture comprising closely related compounds, such as sugar alcohols. In the method the mixture is contacted with an adsorbent, whereby the anhydrosugar alcohols are selectively adsorbed. The anhydrosugar alcohols can be recovered by desorption from the adsorbent, using a desorbing solvent.
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Paragraph 0092; 0093; 0094
(2013/07/25)
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- A simple O-sulfated thiohydroximate molecule to be the first micromolar range myrosinase inhibitor
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New non-hydrolyzable analogues of glucosinolates have been prepared. Myrosinase inhibition was observed with modified aglycon moieties, even bulky phenothiazine analogue 6 gave reasonable inhibition. The simplest structure 8 derived from dimethylaminoethanethiol has shown to be the most potent inhibitor with an IC50 of 3.32 μM.
- Cerniauskaite, Deimante,Gallienne, Estelle,Karciauskaite, Henreta,Farinha, Andrea S.F.,Rousseau, Jolanta,Armand, Sylvie,Tatibou?t, Arnaud,Sackus, Algirdas,Rollin, Patrick
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scheme or table
p. 3302 - 3305
(2009/08/09)
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- INTEGRATED CONTINUOUS PROCESS FOR ANHYDRO SUGAR ALCOHOL MANUFACTURE
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An integrated continuous process is disclosed for the manufacture of high purity, polymer grade dianhydro sugar alcohols, such as isosorbide, by the dehydration of corresponding sugar alcohols. The water vapors evolved during the dehydration are used to separate product dianhydro sugar alcohols from the high boiling byproducts in the reaction mass. The product is recovered from the vapor stream as high purity crystals. The high boiling reaction byproducts are recycled.
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Page/Page column 21-23
(2008/06/13)
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- Original synthesis of linear, branched and cyclic oligoglycerol standards
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A variety of authentic standards of linear, branched and cyclic oligomers of glycerol, with well-defined structures and degrees of polymerisation from 2 to 5, have been efficiently synthesised. Linear oligomers were obtained by means of a convergent approach based on regioselective opening of bis(epoxides) with solketal; branched compounds were synthesised using oxidative cleavage of the corresponding anhydrohexitols as the key step. A 6-exo-trig halocyclisation reaction involving heteroatom-tethered unsaturated alcohols permitted an efficient synthesis of the precursors of selected cyclic dimers; larger cyclic oligomers were prepared by two one-pot Williamson reactions using a ditriflate derived from diglycerol. All these methodologies permitted further scaling up.
- Cassel, Stephanie,Debaig, Catherine,Benvegnu, Thierry,Chaimbault, Patrick,Lafosse, Michel,Plusquellec, Daniel,Rollin, Patrick
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p. 875 - 896
(2007/10/03)
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- Synthesis, aggregation, and chiroptical properties of chiral, amphiphilic dendrimers
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The syntheses of amphiphilic dendrimers based on 3,5-dihydroxybenzyl alcohol containing tri-or tetrafunctional chiral central cores and allyl ester termini are described. Water solubility is imparted to the dendrimers via a palladium-catalyzed deprotection of the peripheral allyl esters. This method affords complete deprotection of the carboxylate surface because, in contrast to the basic hydrolysis of methyl ester termini, the solubility of partially hydrolyzed intermediates is maintained throughout the course of the deprotection, thereby avoiding precipitation during the reaction. Chiroptical analysis indicates that the structure of the dendrimers collapses in water, resulting in an increased steric effect upon the central core that is manifested by lower optical rotatory power. However, contributions to the chiroptical properties from the dendron branch segments were not evident in water or organic media, suggesting that chiral substructures were not developing in the branch segments of the dendrimers. Multiangle light scattering studies revealed that the dendrimers experienced significant aggregation in aqueous media that decreased at higher generations. This behavior could be rationalized by a change in conformational preference from a disklike conformation at low generations to a more globular conformation at higher generations.
- Laufersweiler,Rohde,Chaumette,Sarazin,Parquette
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p. 6440 - 6452
(2007/10/03)
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- Synthesis of 3-deoxy-3-nucleobase-2,5-anhydro-D-mannitol: A novel class of hydroxymethyl-branched isonucleosides
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A concise synthesis of 3-deoxy-3-nucleobase-2,5-anhydro-D-mannitol 6(a- d) has been achieved, using the deamination of 2-amino-2-deoxy-D-glucose to construct in one step the sugar skeleton with the desired sense of chirality at each asymmetric center. The selective dibenzoylation of 2,5-anhydro-D- mannitol 9 was investigated, and the key epoxide intermediate 13 was obtained in good yield via an intramolecular Mitsunobu reaction. The process of opening of epoxide 13 by nucleobases appeared to be regioselective. (C) 2000 Elsevier Science Ltd.
- Lei,Min,Zhang
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p. 2899 - 2906
(2007/10/03)
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- Synthesis of Selectively Labeled D-Fructose and D-Fructose Phosphate Analogues Locked in the Cyclic Furanose Form
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2,5-Anhydroglucitol and 2,5-anhydromannitol and their 6-phosphate and 1,6-diphosphate derivatives are cyclic analogues of the α and β anomers of D-fructofuranose, D-fructofuranose-6-phosphate, and D-fructofuranose-1,6-diphosphate. They were synthesized from protected D-mannose or D-glucose. The synthetic method was developed with emphasis on selective 2H labeling of these compounds, as a model for 3H incorporation, which will be used for further biochemical studies. A key cyclization step, based on a benzyl ether nucleophilic attack on an activated alcohol, constructed the ring system. The stereochemistry at C2 (α/β anomers) and at C5 (D sugar) was controlled by selective epimerizations. Mono- and diphosphate analogues were obtained from the same intermediate by changing the sequence of deprotection and phosphorylation steps.
- Persky, Rachel,Albeck, Amnon
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p. 5632 - 5638
(2007/10/03)
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- Preparation of 2,5-anhydrohexitols (part I). Silicon-directed stereocontrolled cyclization
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Stereoselective chain-extension of carbohydrate aldehydes with the hydroxymethylating reagent (dimethylphenylsilyl)methylmagnesium chloride (1) followed by acid-mediated cyclization gives access to 2,5-anhydro-hexitols. The stereoselectivity of the ring closure depends on the nature of the acid, i.e., treatment with excess BF3·Et2O or catalytic H2SO4 leads to tetrahydrofurans with 2,3-cis or 2,3-trans configuration, respectively. Concomitant elimination is effectively suppressed in case of cyclisation of the more sterically hindered isopropyl substituted silanes.
- Van Delft, Floris L.,Valentijn, A. Rob P.M.,Van Der Marel, Gijs A.,Van Boom, Jacques H.
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p. 165 - 190
(2007/10/03)
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- Synthesis of dendrimers containing 2,5-anhydro-D-mannitol as a chiral, tetrafunctional central core with C2 symmetry
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The synthesis of first through third generation dendrimers containing a chiral, tetrafunctional core and allyl ester termini is described. The molar rotations of the dendrimers were observed to become less negative with increasing generation; however, the rotations of the dendrimers were more negative than the starting central core.
- Rohde, Jason M.,Parquette, Jon R.
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p. 9161 - 9164
(2007/10/03)
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- Synthesis of homo-C-D4T and homo-C-thymidine
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β-C-Vinyl glycoside of D-arabinofuranose was converted to the β-C- hydroxymethyl glycoside 12 which was condensed with N-3-benzoyl thymine under Mitsunobu conditions to furnish homo-C-analog 14 of the 2',3'-dideoxy-2',3'- didehydrothymidine (D4T). Synthesis of the homo-C-thymidine 18 was accomplished by the same procedure from compound 15.
- Doboszewski, Bogdan
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p. 1049 - 1052
(2007/10/03)
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- Sequential Removal of Monosaccharides from the Reducing End of Oligosaccharides. 2. Fundamental Studies of a Reaction between Hydrazino Compounds and Sugars Having a Glycosyl Moiety on a Carbon Atom Adjacent to a Carbonyl Group
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Hydrazine and certain hydrazino derivatives react with sugars having a glycosidic substituent, where the glycosyl moiety is located on a carbon atom adjecent to an aldehyde or keto group of the aglycon, resulting in cleavage of the glycosidic linkage.The reaction proceeds whether the glycon is of the α or β configuration.The released glycosyl moiety, in the presence of excess hydrazino compound, reacts further to give a hydrazone derivative.Removal of the hydrazone group gives the reducing sugar derived from the glycon.
- Bendiak, Brad,Salayan, Mary E.,Pantoja, Mario
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p. 8245 - 8256
(2007/10/03)
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- A simple conversion of polyols into anhydroalditols
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A simple procedure, which consists of direct heating of pyridinium chloride and the starting material, is described for the dehydration of alditols. Anhydroalditols, of great interest for various applications, are thus obtained, and the selectivity of the reaction is discussed. Some selective protections for further uses of these products are studied.
- Duclos,Fayet,Gelas
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p. 1087 - 1090
(2007/10/02)
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- MECHANISMS OF PYROLYSIS OF POLYSACCHARIDES: CELLOBIITOL AS A MODEL FOR CELLULOSE
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The pyrolysis of cellobiitol has been studied as a model for cellulose.The products were determined from pyrolysis at 350 deg C in vacuo and at 350 deg C and at 171 deg C at atmospheric pressure.In vacuo, a 32percent yield of 1,6-anhydro-β-D-glucopyranose (levoglucosan 5) and a 70percent yield of D-glucitol and its anhydrides were obtained, but under atmospheric pressure these yields were much lower.A mechanism is postulated in which the first step in the pyrolysis is a heterolytic scission of the glucosidic linkage to produce a glucosyl cation and a glucitol anion.The formeryields the volatile levoglucosan by intramolecular attack of O-6 on the C-1 cation and this reaction is favored in vacuo because of the resultant efficient removal of 5.The glucitol is obtained predominantly as anhydrides, which are volatile in the vacuum pyrolysis.Lower tempeature (171 deg C) pyrolysis gave no 5.The glucosyl cation under such conditions is believed to undergo intermolecular nucleophilic substitution with hydroxyl groups from unreacted starting material and from glucitol to produce oligosaccharides.
- Lowary, Todd L.,Richards, Geoffrey N.
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- Synthesis of rigid, chiral 1,5-diamino-3-oxapentanes and incorporation into chiral macrocyclic polyether ligands
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The synthesis of 2,5-anhydro-1,6-di-C-amino-1,6-dideoxy-3,4-di-O-methyl-D-mannitol 11 and its N,N'-dimethyl analogue 15 are described, as are couplings to bis-tartaro-18-crown-6 1 to give a macrobicyclic cryptand 16, and macrocycles 17 and 18 bearing four lateral groups, which are potential precursors of a cylindrical stacked macrocyclic system such as 6.
- Lehn, Jean-Marie,Potvin, Pierre G.
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p. 195 - 200
(2007/10/02)
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- An Efficient Synthesis of Anhydroalditols and Allyl C-Glycosides
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Efforts to expedite production of anhydroalditols have led to a new, efficient synthesis of these compounds from alkyl glycosides.Silylation of the glycoside followed by reductive cleavage in the presence of triethylsilane and trimethylsilyl trifluoromethanesulfonate were carried out in the same reaction flask.Subsequent aqueous workup gave excellent yields of anhydroalditol(s).In some cases ring contraction was observed, but the use of bulkier silyl protecting groups gave greater yields of the expected product.This method was also shown to be an efficient means to prepare allyl C-glycosides, without any independent protecting or activating step, by simply replacing triethylsilane with allyltrimethylsilane in the synthetic scheme.
- Bennek, John A.,Gray, Gary R.
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p. 892 - 897
(2007/10/02)
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- STRUCTURAL STUDIES OF A NEUTRAL POLYMERIC FRACTION FROM THE LYPOPOLYSACCHARIDE OF SERRATIA MARCESCENS C.D.C.1783-57 (O14:H9)
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A neutral polymer of glucose, galactose, and 2-acetamido-2-deoxyglucose (molar ratios 1:1:2) has been isolated from the lypopolysaccharide of Serratia marcescens strain C.D.C. 1783-57 (O14:H9).Degradative and spectroscopic studies established that the polysaccharide has a branched tetrasaccharide repeating-unit of the structure shown.The polymer was absent from other strains of serogroup O14 studied, but a polymer differing only in the configuration of the glucose residue has previously been isolated from a strain of S. marcescens O8.The polymer from strain C.D.C. 1783-57 also shares structural features with the Escherichia coli O18 antigen, which is known to be serologically related to the S. marcescens O8 antigen.
- Bridgen, Christopher J.,Wilkinson, Stephen G.
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- 2,5-ANHYDRO-D-HEXITOLS: SYNTHESES OF 2,5-ANHYDRO-D-ALTRITOL AND 2,5-ANHYDRO-D-IDITOL
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2,5-Anhydro-D-altritol (2a) and the previously-unknown 2,5-anhydro-D-iditol (3a) have been prepared from 2,5-anhydro-D-mannitol (1a).The preparation of 3a from the intermediate epoxide 7b is particularly sensitive to pH, and a mechanism is proposed to explain this.Attention is drawn to the limitations of the trifluoroperacetic acid-disodium hydrogenphosphate procedure for the epoxidation of alkenes of diminished reactivity.
- Otero, Dario A.,Simpson, Ronald
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- THE FORMATION OF 3,4,6-TRI-O-BENZYL-2,5-ANHYDRO-L-IDITOL FROM 2,3,4,6-TETRA-O-BENZYL-D-GLUCOPYRANOSE. INTRAMOLECULAR DISPLACEMENT OF A SECONDARY MESYLOXY GROUP BY A BENZYLOXY GROUP, IN THE PRESENCE OF CESIUM PROPIONATE
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The reaction between 2,3,4,6-tetra-O-benzyl-1,5-di-O-mesyl-D-glucitol and cesium propionate in dimethylformamide at 100 deg C leads to an almost quantitative conversion into 3,4,6-tri-O-benzyl-1-O-propionyl-2,5-anhydro-L-iditol.Closure of the anhydro ring appears to entail anchimeric assistance by the 2-O-benzyl substituent in an SN2 displacement at C-5, leading to an inversion at the latter position.Probable contributors to the marked regio- and stereoselectivity observed for the reaction are a unique property of cesium propionate as compared with other carboxylate salts, large differences in rate between competing reactions, and a geometry highly favorable to an intramolecular displacement process.Conformational properties of 2,5-anhydro-L-iditol, as well as of isomeric 2,5-anhydro-D-mannitol, are described, based on nmr evidence.
- Rao, Vanga S.,Perlin, Arthur S.
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p. 886 - 890
(2007/10/02)
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- THE CHEMICAL-TRANSFORMATION PRODUCTS OF 1,6-DIBROMO-1,6-DIDEOXYGALACTITOL AND 1,2:5,6-DIANHYDROGALACTITOL IN AQUEOUS SOLUTION
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After hydrolysis of 1,6-dibromo-1,6-dideoxygalactitol (1) and 1,2:5,6-dianhydrogalactitol (2), 11 compounds were isolated, three of them as tritylated derivatives.Their structures were established on the basis of chemical evidence and, for four compounds, by X-ray diffraction.The main product of the hydrolysis of 1 was 3,6-anhydro-1-bromo-1-deoxy-DL-galactitol; the end-products of the hydrolysis of 2 were 1,5-anhydro-DL-galactitol, 2,5-anhydro-DL-altriol and galactiotol.
- Vidra, Ildiko,Simon, Kalman,Institoris, Laszlo,Csoeregh, Ingeborg,Czugler, Matyas
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- Acid Catalyzed Dehydration of Alditols. Part I. D-Glucitol and D-Mannitol
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The acid catalyzed dehydration of D-glucitol and D-mannitol has been studied using 13C NMR spectroscopy to monitor the reactions.The products formed were identified and rate constants were measured.Dehydration of (1S)-1-2H-D-mannitol with 3 M sulfuric acid was shown to yield (1R)-1-2H-1,4:3,6-dianhydro-D-mannitol, showing that dehydration of D-mannitol to 1,4-anhydro-D-mannitol and, subsequently, to the 1,4:3,6-dianhydride takes place with inversion at the primary carbon atom.
- Bock, Klaus,Pedersen, Christian,Thoegersen, Henning
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p. 441 - 450
(2007/10/02)
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