Selective Conversion Of Fructose Research Articles

Selective conversion of fructose into 5-ethoxymethylfurfural over green catalyst

In this study, selective formation of 5-ethoxymethylfurfural (EMF) from one-pot conversion of fructose in a co-solvent of ethanol with tetrahydrofuran over green SO3H-CD carbon was investigated for the first time using an ultrasonic system. The maximum EMF yield of 74% with 100% fructose conversion was achieved in mild conditions. Moreover, the better selectivity and the longer recyclability (eight cycles) for EMF production via particular reactions such as fructose dehydration and etherification were obviously found while the formation of 5-hydroxymethylfurfual, ethyl levulinate or humins was inhibited using SO3H-CD carbon, comparing to commercial catalysts such as Amberlyst-35, SiO2-Tosic acid and Al2O3.

Protonic acid catalysis of sulfonated carbon material: Tunable and selective conversion of fructose in low-boiling point solvent

Catalytic conversion of various carbohydrates into 5-hydroxymethylfurfural (HMF) and 5-ethoxymethylfurfural (EMF) was efficiently conducted by sulfonated carbon material (polyurethane based catalyst, abbreviated as PU-Cat). In the preparation process of catalyst, the tetrahydrofuran was reclaimed. PU-Cat exhibited excellent performance in the synthesis of HMF and EMF from fructose-based carbohydrates. Firstly, the dehydration of fructose into HMF was smoothly carried out in the low-boiling solvent (1, 4-dioxane), which was catalyzed by PU-Cat at 140 °C. The highest yield of HMF was up to 70.1% with full conversion of fructose in 1, 4-dioxane for 2 h. Then, the one-pot conversion of fructose into EMF was also successfully performed in the ethanol/1, 4-dioxane (V/V=70:30) at 140 °C for 2 h, and 66.0% yield of EMF was obtained. Finally, PU-Cat can be recycled five times without significant reduction in catalytic activity.

Simple and selective conversion of fructose into HMF using extractive-reaction process in microreactor

An extractive-reaction process for the synthesis of HMF from fructose was implemented in microreactor. Experimental conditions were 10 wt.% fructose in water, MIBK as extracting solvent and HCl as catalyst in a temperature window of 120–160 °C, a MIBK/H2O ratio 1 to 9 and an HCl concentration of 0.25–2 M. The dehydration of fructose to HMF is achieved in less than 40s with a total HMF yield higher than 90% at 150 °C. Aqueous and organic phase spontaneously separate at the outlet of the reactor and HMF is obtained in MIBK with a yield of 80% and a purity of 92%.

Direct Conversion of Carbohydrates into 5‐Ethoxymethylfurfural (EMF) and 5‐Hydroxymethylfurfural (HMF) catalyzed by Oxomolybdenum complexes

AbstractThis work reports the first methodology for one‐pot synthesis of 5‐ethoxymethylfurfural (EMF) and 5‐hydroxymethylfurfural (HMF) from various carbohydrates catalyzed by oxo‐molybdenum complexes. The best results of EMF (53‐60 %) were obtained using a mixture of ethanol/THF (5:2) catalyzed by MoO2Cl2(H2O)2 at 120 °C, after 17 h. This dioxo‐molybdenum complex also promoted the synthesis of EMF from other carbohydrates such as inulin and sucrose. The selective conversion of fructose into HMF was achieved in good yield (75 %) from fructose using MoO2Cl2(H2O)2 in DMSO at 120 °C after 30 minutes. This novel methodology has the advantages of using an inexpensive, environmental friendly and air stable catalyst with an easy preparation.

The effect of a sucrose-enriched diet on the metabolism of intravenously administered fructose in baboons.

There is a highly significant rise in the fasting serum glyceride concentrations of both male and female baboons in the first 3 weeks of consumption of a 75-ρercent by weight sucrose diet, reaching a peak between the 2nd and 4th weeks of the diet. Even at 10 weeks the mean values are higher than the pre-diet levels. There is no significant change in the fasting cholesterol or phospholipid concentrations. There is no detectable change in the overall rate of fructose metabolism when fructose is given intravenously at the end of the high sucrose diet as compared with before the diet. There is no significant change in the glyceride <sup>14</sup>C-specific activity following intravenous injection of <sup>14</sup>C-fructose at the end of the dietary period as compared with the beginning in either male or female baboons. This suggests that if there has been overall increase in the rate of glyceride synthesis this has not occurred solely as a result of a selective conversion of fructose to glyceride, but involves all glyceride precursor substances. The pattern of change in serum lipid and glucose concentrations following fructose injection is no different at the end of the dietary period compared with the beginning. There is a suggestion of increased glucose assimilation during the dietary period. It is concluded that the increase in incorporation into the serum glyceride of <sup>14</sup>C-sucrose given orally at the end of a period of consuming 75% sucrose is primarily due to an increased rate of absorption of the products of sucrose hydrolysis rather than to any increase in the rate of metabolism of fructose.