Effect of carbon chain length on catalytic C O bond cleavage of polyols over Rh-ReOx/ZrO2 in aqueous phase
作者:Achraf Sadier、Noémie Perret、Denilson Da Silva Perez、Michèle Besson、Catherine Pinel
DOI:10.1016/j.apcata.2019.117213
日期:2019.9
-tetraols, -triols, -diols, and hexanols) is achievable by hydrogenolysis of erythritol, xylitol, and sorbitol over supported-bimetallic Rh-ReOx (Re/Rh molar ratio 0.5) catalyst, respectively. After validation of the analytical methodology, the effect of some reaction parameters was studied. In addition to CO bond cleavage by hydrogenolysis, these polyols can undergo parallel reactions such as epimerization
Preparation of 2,5-Anhydrohexitols (Part Ii). Intramolecular Nucleophilic Substitution of Cyclic Sulfates
作者:Floris L. van Delft、A. Rob、P.M. Valentijn、Gijs A. van der Marel、Jacques H. van Boom
DOI:10.1080/07328309908543990
日期:1999.1.1
4-di-O-benzyl-5,6-O-cyclic sulfates 5, 16 and 25, derived from D-arabinose, D-ribose and D-xylose, respectively, are useful precursors in the synthesis of 2,5-anhydrohexitols. 5-Exo-tet cyclization of compounds 5, 16, and 25 under the influence of base leads to the predominant or exclusive formation of the corresponding tetrahydrofuran derivatives
The invention includes a method of dehydration of a sugar using a dehydration catalyst and a co-catalyst within a reactor. A sugar is introduced and H
2
is flowed through the reactor at a pressure of less than or equal to about 300 psig to convert at least some of the sugar into an anhydrosugar product. The invention includes a process for producing isosorbide. A starting material comprising sorbitol is flowed into a reactor. H
2
is counter flowed through the reactor. The starting material is exposed to a catalyst in the presence of a co-catalyst which comprises at least one metal. The exposing is conducted at a hydrogen pressure of less than or equal to 300 psig within the reactor and the hydrogen removes at least some of any water present during the exposing and inhibits formation of colored byproducts.
An enhanced process for the production of a dianhydrosugar, such as isosorbide, from the corresponding sugar alcohol is described. The sugar alcohol is combined with an acid catalyst and reacted at elevated temperatures and at atmospheric pressure, eliminating the need for a vacuum. High selectivity and yields are achieved.
[EN] ISOIDIDE MANUFACTURE AND PURIFICATION<br/>[FR] PRODUCTION D'ISOIDIDE ET PURIFICATION
申请人:ARCHER DANIEL MIDLAND COMPANY
公开号:WO2016137833A1
公开(公告)日:2016-09-01
Methods are provided for the conversion of isosorbide to isoidide, wherein the isosorbide contains sorbitan impurities. The impurities in the isosorbide subjected to epimerization are converted to hydrodeoxygenation products. A method for synthesizing isoidide, comprising, providing an isosorbide containing one or more sorbitans; and, epimerizing the isosorbide to form an epimerization product comprising isoidide and hydrodeoxygenation products.