Microwave assisted synthesis of dehydrated sugar derivatives hydroxymethylfurfural, levulinic acid, anhydrosugar alcohols, and ethers thereof

摘要

Methods for the production of dehydrated sugars and derivatives of dehydrated sugars using microwave (MW) irradiation and methods of purifying the same are described. The dehydrated sugars derivatives include 5-hydroxymethyl-2-furfural (HMF) and anhydrosugar alcohols such as sorbitans and isosorbide. The derivatives include HMF ethers, levulinic acid esters, and ether derivatives of the anhydrosugar alcohols. The described methods require lower reaction temperatures and shorter reaction times than similar non microwave mediated reactions known in the art. Typical reaction conditions are 120-210° C., and typical reaction times are 30 minutes or less.

主权项

1. A method of producing a dehydrated sugar derivative comprising,
a. forming a reaction mixture comprising a solvent and a reactant selected from the group consisting of a hexose, a sugar alcohol, and an anhydrosugar alcohol, and an acidic catalyst selected from the group consisting of a heterogeneous solid acid substrate and a homogeneous acid; and b. contacting the reaction mixture with microwave radiation to achieve a temperature of between 160° C. and 210° C. for a time sufficient to convert at least 40% of the reactant into at least one desired dehydrated sugar derivative product,
wherein the reaction contains a R-alcohol selected from the group consisting of an alkyl group, an allyl group, a cycloalkyl group, an aryl group, and combinations of any thereof; whereinthe reactant is present in a concentration of at least 20%; andthe R-alcohol is the solvent in the reaction mixture; and,the dehydrated sugar derivative is selected from the group consisting of an R-ether or R-ester of the dehydrated sugar.