Dehydration of glucose

Gonzales and Laird145 have shown that smectites abiotically catalyze dehydration of glucose to form furfural under conditions similar to those found in soils. Four smectite clay minerals were used (saturated with Na, Ca, Fe, or Al), and the formation of HMF and furfural was detected by high-pressure liquid chromatography. The polymerization of furfural may thus be a pathway to the formation of new humic materials in soils. 

K. Lourvanij and G. L. Rorrer, Reaction rates for the partial dehydration of glucose to organic acids in solid-acid, molecular-sieving catalyst powders,... 

Some naturally occurring polymers such as cellulose, starch, wool, and silk are classified as condensation polymers, since one can postulate their synthesis from certain hypothetical reactants by the elimination of water. Thus cellulose can he thought of as the polyether formed by the dehydration of glucose. Carothers included such polymers by defining condensation polymers as those in which the formula of the repeating unit lacks certain atoms that are present in the monomer(s) from which it is formed or to which it may be degraded. In this... 

Scheme 8 Tandem isomerization/dehydration of glucose over Zr02 and Ti02...

Based on these results and the disadvantageously high volatility of hexane, Huber et al. decided to develop another approach utilizing 5-hydroxymethylfurfural (5-HMF) or furfural, compounds that can be obtained from the dehydration of glucose or xylose, respectively [54-57]. The production of Cg-Ci5 alkenes from these furans is achievable by sequential aldol condensation with acetone followed by hydrogenation... 

Apart from dehydration of glucose or fructose in the presence of alcohols and acid catalysts, synthesis strategies via 5-(chloromethyl)furfural and subsequent heating in the desired alcohol or utilizing furfuryl alcohol as feedstock have been demonstrated [89-98], While 5-(chloromethyl)furfural may be derived in one step based on cellulose, a synthesis procedure starting from furfuryl alcohol utilizes hemicellulose as feedstock, bridging the C5 and C6 carbohydrate value chain. 

The removal of water from initially formed biomass sugars is an important process for the production of primary biorefinery building blocks. Of particular interest are 5-hydrox-ymethylfurfural and levulinic acid (from the dehydration of glucose or other C6 sugars) and furfural (from xylose dehydration). Recent research has led to new catalytic processes for the production of each of these materials. 

Levulinic Acid. Dehydration of glucose or other monomeric and polymeric C6 sugars leads to the direct formation of levulinic acid (LA) as a potential primary building block for the biorefinery, and several reviews have described its potential commercial utility 477,478 The preparation of levulinic acid is not difficult, although the mechanism of its formation from carbohydrates is complex, and offers several alternative decomposition pathways (equation 3).479... 

Dehydration of glucose in the presence of microporous pillared clays has also been explored but, the selectivity to levulinic acid was low.480... 

Lourvanij, K. and Rorrer, G. L., Dehydration of glucose to organic-acids in microporous pillared clay catalysts. 

This is the method for an estimation of biochemical activity of microorganisms in active sludge by oxidation processes of organic compounds. It is based on the dehydration of glucose added to the compost. 

High yields (>90%) of both CMF and BMF have been reported by treatment of 3-deoxyglucosone, which is the product of a single dehydration of glucose, with the corresponding HX acids [126]. 

Y. Qu, C. Huang, Y. Song, J. Zhang, B. Chen, Efficient dehydration of glucose to 5-hydroxymethylfurfural catalyzed by the ionic liquid, l-hydroxyethyl-3-methylimidazolium tetrafluoroborate, Bioresour. Technol. 121 (2012) 462-466. 

Zeng W, Cheng D-G, Zhang H, Chen F, Zhan X. Dehydration of glucose to levuhnic acid over MFl-type zeohte in suhcritical water at moderate conditions. React Kinet Mech Catal 2010 100 377-84. 

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