478506-38-6Relevant articles and documents
Integration of Enzymatic and Heterogeneous Catalysis for One-Pot Production of Fructose from Glucose
Sun, Jiankui,Li, Helong,Huang, Hongzhi,Wang, Bo,Xiao, Ling-Ping,Song, Guoyong
, p. 1157 - 1162 (2018/03/21)
The search for efficient routes for the production of fructose from biomass-derived glucose is of great interest and importance, as fructose is a highly attractive substrate in the conversion of cellulosic biomass into biofuels and chemicals. In this study, a one-pot, multistep procedure involving enzyme-catalyzed oxidation of glucose at C2 and Ni/C-catalyzed hydrogenation of d-glucosone at C1 selectively gives fructose in 77 % yield. Starting from upstream substrates such as α-cellulose and starch, fructose was also generated with similar efficiency and selectivity by the combination of enzymatic and heterogeneous catalysis. This method constitutes a new means of preparing fructose from biomass-derived substrates in an efficient fashion.
CONVERSION OF GLUCOSE TO SORBOSE
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Paragraph 0087, (2014/10/29)
The present invention is directed to methods for preparing sorbose from glucose, said method comprising: (a) contacting the glucose with a silica-containing structure comprising a zeolite having a topology of a 12 membered-ring or larger, an ordered mesoporous silica material, or an amorphous silica, said structure containing Lewis acidic Ti4+ or Zr4+ or both Ti4+ and Zr4+ framework centers, said contacting conducted under reaction conditions sufficient to isomerize the glucose to sorbose. The sorbose may be (b) separated or isolated; or (c) converted to ascorbic acid.
Titanium-beta zeolites catalyze the stereospecific isomerization of d -glucose to l -sorbose via intramolecular C5-C1 hydride shift
Gounder, Rajamani,Davis, Mark E.
, p. 1469 - 1476 (2013/07/26)
Pure-silica zeolite beta containing Lewis acidic framework Ti4+ centers (Ti-Beta) is shown to catalyze the isomerization of d-glucose to l-sorbose via an intramolecular C5-C1 hydride shift. Glucose-sorbose isomerization occurs in parallel to glucose-fructose isomerization on Ti-Beta in both water and methanol solvents, with fructose formed as the predominant product in water and sorbose as the predominant product in methanol (at 373 K) at initial times and over the course of >10 turnovers. Isotopic tracer studies demonstrate that 13C and D labels placed respectively at the C1 and C2 positions of glucose are retained respectively at the C6 and C5 positions of sorbose, consistent with its formation via an intramolecular C5-C1 hydride shift isomerization mechanism. This direct Lewis acid-mediated pathway for glucose-sorbose isomerization appears to be unprecedented among heterogeneous or biological catalysts and sharply contrasts indirect base-mediated glucose-sorbose isomerization via 3,4-enediol intermediates or via retro-aldol fragmentation and recombination of sugar fragments. Measured first-order glucose-sorbose isomerization rate constants (per total Ti; 373 K) for Ti-Beta in methanol are similar for glucose and glucose deuterated at the C2 position (within a factor of ～1.1), but are a factor of ～2.3 lower for glucose deuterated at each carbon position, leading to H/D kinetic isotope effects expected for kinetically relevant intramolecular C5-C1 hydride shift steps. Optical rotation measurements show that isomerization of d-(+)-glucose (92% enantiomeric purity) with Ti-Beta in water (373 K) led to the formation of l-(-)-sorbose (73% enantiomeric purity) and d-(-)-fructose (87% enantiomeric purity) as the predominant stereoisomers, indicating that stereochemistry is preserved at carbon centers not directly involved in intramolecular C5-C1 or C2-C1 hydride shift steps, respectively. This new Lewis acid-mediated rearrangement of glucose to sorbose does not appear to have a metalloenzyme analog.
HYDROXIDE-CATALYZED ISOMERIZATION OF D-(1-13C)MANNOSE: EVIDENCE FOR THE INVOLVEMENT OF 3,4-ENEDIOLS
King-Morris, Melinda J.,Serianni, Anthony S.
, p. 29 - 36 (2007/10/02)
The KOH-catalyzed isomerization of D-(1-13C)mannose under anaerobic conditions was studied by 13C-n.m.r. spectroscopy.D-(1-13C)Glucose and D-(1-13C)fructose are generated during the reaction, as expected.In addition, however, (6-13C)glucose, (6-13C)mannose, and (6-13C)fructose are produced in small proportions, possibly via symmetrical 3,4-enediol intermediates.The involvement of the latter structures in 13C-label shifting is inferred from the observation of (1-13C)sorbose and (6-13C)sorbose in the reaction mixture.
