Furfural, also called 2-furaldehyde, is the best-known member of the furan family and a source of other technically important furans. It is a colorless liquid, which is prone to darkening on exposure to air. Furfural is the sole source for the industrial production of furfuryl alcohol, tetrahydrofurfuryl alcohol, furoic acid, furfurylamine, methylfuran, and furan. It can be classified as 5 methyl furfural, hydroxymethyl furfural, methyl furfural, and chloromethyl furfural. 5 methyl furfural is a natural product found in Campsis grandiflora, Castanopsis cuspidata, and other organisms. It can be used as a food additive. It is also commonly used as a synthetic intermediate. Hydroxymethyl furfural is a key intermediate used in the production of biomass-derived fuels and polymers.
