- 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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- Hydrophilic sulfonic acid-functionalized micro-bead silica for dehydration of sorbitol to isosorbide
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Different (3-mercaptopropyl)trimethoxysilane (MPTS) loadings of sulfonic acid-functionalized micro-bead silica (SA-SiO2) were prepared by silylation and oxidation, and characterized by elemental analysis, SEM, FT-IR, TGA, NH3-TPD, BET N2 adsorption-desorption and 13C NMR CP/MAS. The as-prepared SA-SiO2 showed strong hydrophilic nature and excellent catalytic performance for dehydration of sorbitol to isosorbide. The selectivity to isosorbide is obviously affected by the MPTS loading. Using SA-SiO2 as a solid catalyst with 60.5% MPTS loading, 100% sorbitol conversion and 84% yield of isosorbide are achieved at 120 °C for 10 h under vacuum. The catalyst was reused 10 times without noticeable loss of activity and selectivity.
- Shi, Jun,Shan, Yuhua,Tian, Yuan,Wan, Yu,Zheng, Yitian,Feng, Yangyang
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p. 13514 - 13521
(2016/02/12)
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- Production of cyclic ether and a recycling method of using ionic liquids
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PROBLEM TO BE SOLVED: To provide a method for manufacturing cyclic ethers having a high environmental friendliness capable of obtaining, without using a supercritical fluid or high-pressure reaction vessel, cyclic ethers led by isosorbide in favorable yields within brief periods and a method for recycling an ionic liquid used for the same.SOLUTION: The provided method for manufacturing cyclic ethers comprises a step of dehydrating a polyhydric alcohol possessing at least three hydroxyl groups by heating the polyhydric alcohol with microwaves by using an ionic liquid as a reaction solvent. A method for recycling the ionic liquid used for the same is also provided.
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Paragraph 0033; 0036
(2017/06/15)
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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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- 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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- 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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