63526-48-7Relevant articles and documents
Kinetic analysis of hexose conversion to methyl lactate by Sn-Beta: Effects of substrate masking and of water
Tosi, Irene,Riisager, Anders,Taarning, Esben,Jensen, Pernille Rose,Meier, Sebastian
, p. 2137 - 2145 (2018)
Simple sugars show promise as substrates for the formation of fuels and chemicals using heterogeneous catalysts in alcoholic solvents. Sn-Beta is a particularly well-suited catalyst for the cleavage, isomerization and dehydration of sugars into more valuable chemicals. In order to understand these processes and save resources and time by optimising them, kinetic and mechanistic analyses are helpful. Herein, we study substrate entry into the Sn-Beta-catalysed methyl lactate process using abundant hexose substrates. NMR spectroscopy is applied to show that the formation of methyl lactate occurs in two kinetic regimes for fructose, glucose and sucrose. The majority of methyl lactate is not formed from the substrate directly, but from methyl fructosides in a slow regime. At 160 °C, more than 40% of substrate carbon are masked (i.e. reversibly protected in situ) as methyl fructosides within a few minutes when using hydrothermally synthesised Sn-Beta, while more than 60% methyl fructosides can be produced within a few minutes using post-synthetically treated Sn-Beta. A significant fraction of the substrate is thus masked by rapid methyl fructoside formation prior to subsequent slow release of fructose. This release is the rate-limiting step in the Sn-Beta-catalysed methyl lactate process, but it can be accelerated by the addition of small amounts of water at the expense of the maximum methyl lactate yield.
A Systematic Study of Metal Triflates in Catalytic Transformations of Glucose in Water and Methanol: Identifying the Interplay of Br?nsted and Lewis Acidity
Bodachivskyi, Iurii,Kuzhiumparambil, Unnikrishnan,Williams, D. Bradley G.
, (2019/04/25)
The specific type of acidity associated with the given metal trifloromethanesulfonates (Br?nsted or Lewis acidity) dramatically influences the course of reactions, and it is possible to select for disaccharides, fructose, methyl glucosides, or methyl levulinate. Glucose is transformed into a range of value-added molecules in water and methanol under the action of acidic metal triflates as catalysts, including their analogous Br?nsted acid-assisted or Br?nsted base-modified systems. A systematic study is presented of a range of metal triflates in methanol and water, pinning down the preferred conditions to select for each product.
Conversion of fructose into 5-hydroxymethylfurfural (HMF) and its derivatives promoted by inorganic salt in alcohol
Liu, Jitian,Tang, Yu,Wu, Kaigui,Bi, Caifeng,Cui, Qiu
experimental part, p. 20 - 24 (2012/03/22)
The conversion of d-fructose to 5-hydroxymethylfurfural (HMF) on a 1 mmol scale was achieved in good yield (68%) using NH4Cl as catalyst in isopropanol at 120 °C. About 3% of 5-i-propoxymethylfurfural was formed. The reaction in ethanol at 100 °C on a 10 g scale gave a total yield of HMF and 5-ethoxymethylfurfural of 42%. No mineral acid such as H2SO 4 and HCl are required.
An approach towards the synthesis of sialyl nucleoside mimetics
Grice, I. Darren,Whelan, Catherine,Tredwell, Gregory D.,Von Itzstein, Mark
, p. 1425 - 1434 (2007/10/03)
An approach towards the synthesis of novel sialyl nucleoside mimetics based on d-fructose is described. The synthesis of these mimetics is achieved in good overall yield in seven steps. The key synthetic step is the coupling reaction of pyrimidine bases (uracil, 5-fluorouracil and cytosine) to the C-1 position of the modified D-tagatofructofuranoside.
MCM-41 materials as catalysts for the synthesis of alkyl fructosides
Van Der Heijden,Van Rantwijk,Van Bekkum
, p. 131 - 147 (2007/10/03)
Alkylation of saccharides combines the essential characteristics of two major renewable classes, viz. triglycerides and carbohydrates, while leading to biofriendly surfactants and emulsifiers. The development of alkylated derivatives of fructose has lagged because no efficient synthesis was available. We have found that mesoporous materials of the MCM-41 type are active and selective catalysts for the alkylation of fructose. Quantitative yields were obtained in the reaction of fructose with lower alcohols, up to C4. For long chain alcohols yields were moderate but the alkyl fructopyranosides could be easily purified. The other isomers could be isolated by chromatography.
Reaction of D-fructose, D-glucose and inulin with alcohols in the presence of iodine; a novel glycosidation procedure
Verhart, Cor G.J.,Fransen, Carel T.M.,Zwanenburg, Binne,Chittenden, Gordon J.F.
, p. 133 - 139 (2007/10/03)
An efficient procedure for the glycosidation of D-fructose and D-glucose catalyzed by iodine is described. The reaction yields mainly alkyl glycofuranosides. Treatment of inulin under similar conditions leads to inter-glycosidic bond cleavage and to formation of alkyl D-fructofuranosides. The reaction conditions are particularly mild and relatively selective.
Methyl α-D-fructofuranoside: Synthesis and Conversion into Carboxylates
Johnson, Louise,Verraest, Dorine L.,Haveren, Jacco van,Hakala, Kimmo,Peters, Joop A.,Bekkum, Herman van
, p. 2475 - 2484 (2007/10/02)
Methyl α-D-fructofuranoside was synthesized by methylation of D-fructose and subsequent isolation of the α-furanoside from the anomeric mixture.This fructofuranoside was used as a starting material for the synthesis of several carboxylates, applying glycolic oxidation, selective oxidation of the primary alcohol function at the C-6 position and carboxymethylation.
THE BEHAVIOUR OF D-FRUCTOSE AND INULIN TOWARDS ANHYDROUS HYDROGEN FLUORIDE
Defaye, Jacques,Gadelle, Andree,Pedersen, Christian
, p. 53 - 66 (2007/10/02)
Inulin and D-fructose are quantitatively converted into a mixture of D-fructose dianhydrides on treatment with anhydrous hydrogen fluoride.Of the six dianhydrides isolated, five are known compounds, whereas one, β-D-fructofuranose β-D-fructopyranose 2,1':3,2'-dianhydride, has not been described hitherto.The structures of two of the known dianhydrides have been revised.The relative amounts of dianhydrides obtained depend on the reaction conditions.The reaction of D-fructose with hydrogen fluoride is shown, using 13C-n.m.r. spectroscopy, to involve D-fructofuranosyl fluoride as a probable intermediate.Dianhydrides are also formed when D-fructose is treated with methanol and sulfuric acid under Fischer glycosidation conditions or with trifluoroacetic acid.
FORMATION AND EQUILIBRATION OF D-FRUCTOSIDES AND 2-THIO-D-FRUCTOSIDES IN ACIDIFIED DIMETHYL SULFOXYDE: SYNTHETIC AND MECHANISTIC ASPECTS
Moody, Wayne,Richards, Geoffrey N.
, p. 201 - 214 (2007/10/02)
A kinetic study of the reaction of ketoses and ketosides under catalysis with very dilute acid to produce the ketosyl carbonium ion is reported, and the subsequent reaction of this ion with alcohol and thiol nucleophiles has been studied.The relative reactivity of D-fructoses and 2-thio-fructosides is discussed, and some tentative conclusions have been reached on the mechanism of their furanoside-pyranoside equilibration.The change in ring size in such systems probably proceeds via an anhydro-D-fructose intermediate, rather than an acyclic intermediate.The synthetic applications of the system have been explored, and it has been shown that both D-fructosides and 2-thio-D-fructosides may be synthesized in good yield.The D-fructofuranosides are best obtained from sucrose as the starting material, whereas the pyranosides are obtained from any readily available D-fructopyranoside (e.g., methyl β) by use of the desired alcohol or thiol, only the β anomers being obtained.Three new 2-thio-D-fructosides are reported.
A specific inhibitor of IgE-antibody formation: n-Pentyl β-D-fructopyranoside
Haraguchi,Yagi,Koda,Inagaki,Noda,Nishioka
, p. 1495 - 1499 (2007/10/02)
n-Pentyl β-D-fructopyranoside significantly suppresses IgE-antibody formation in rats and mice when orally administered, while no formation of hemagglutinin was observed. This is the first compound that is novel in structure and which exhibits a selective inhibition of IgE-antibody formation.