Conversion of biomass-derived monosaccharides to 2-methylfuran in supercritical acetone

Abstract

2-Methylfuran (2-MF) is an important organic intermediate with a wide range of applications in pharmaceutical, pesticide and fine chemical industries. The existing industrial route to 2-MF relies on the energy-intensive, multi-step conversion of xylose-derived furfural via catalytic hydrodeoxygenation, requiring potentially hazardous hydrogen handling. In this study, we present a novel one-pot pathway to directly convert monosaccharides and acetone to 2-MF in supercritical acetone. The reaction conditions, including the dosage of water, reaction temperature, reaction time, and the dosage of xylose were optimized, where (11 mL, 260 ℃, 2 h, 200 mg), a maximum 31.6 C mol% yield of 2-MF was obtained, and substantial yields were obtained for 2,5-dimethyl-3(2H)-furanone (DFR) and 3-hexene-2,5-diketone (HDK), reaching 5.2 C mol% and 13.9 C mol% respectively, representing possible near-complete valorization of the C5 feedstock. Combination DFT calculations and 13C experiments revealed that the reaction proceeded via firstly C-C bond cleavage of xylose to form the C2 fragment by OH- from water or acetone, glycolaldehyde (GA), and the C3 fragments, glycolaldehyde (GA) or dihydroxyacetone (DHA), then GA react with acetone to form 2-MF, and C3 fragments were converted to DFR and HDK by acetone itself. This work not only elucidates a new effective way to produce 2-MF directly, but also highlights the potential of supercritical acetone as a versatile solvent system for biomass valorization.