Thermal decomposition of furans with oxygenated substituents: A combined experimental and quantum chemical study

Abstract Furans are an important class of compounds that can be thermochemical or enzymatically produced from biomass. Despite their importance little is known about the thermal decomposition furans with oxygenated substituents. In this work, influence -CH3, -CH2OH and -CHO functional groups on molecular radical chemistry studied a combined quantum chemical experimental approach using 2-furfuryl alcohol 5-methyl furfural as model components. The calculations show both reactants decompose by ring-opening isomerization reaction through carbene intermediates. latter formed shift hydrogen atom group within furan ring structure. structure accelerates reaction, while it suppresses formation channels compared to other groups. weaker C H O bonds in respectively result higher cannot neglected. This confirmed experimentally analyzing product spectrum beam synchrotron VUV photoionization mass spectrometry at pressure 0.04 bar for temperatures between 923 K 1223 K 973 K 1273 K furfural. For several intermediates observed starting Examples measured radicals those initial reactant homolytic bond scission methyl, allyl, propargyl, 1,2-butadiene-4-yl, 2-furanyl-methyl, 2,5-dihydrofuran-2-yl 1‑hydroxyl-2-furanyl-methyl radicals.