2-Hydroxymethyl-furfural from hexose

Heating a solution of hexoses in a strong non-oxidising acidic conditions, hydroxy methyl furfural is formed. The hydroxymethyl furfural from hexose is usually oxidized further to other products When phenolic compounds such as resorcinol, a-naphthol or enthrone are added, mixture of coloured compounds are formed. ... 

Furfural (from pentoses) Hydroxymethyl-5 furfural (from hexoses)... 

The fermentation inhibitors include furan aldehydes, aliphatic acids, and phenolic compounds. The furan aldehydes, furfural, and hydroxymethyl furfural (HMF), are formed from pentoses and hexoses, respectively (4,5). Several studies indicate that furfural inhibits Saccharomyces cerevisiae, at least when present in high concentrations (6-10). HMF has a similar effect (11,12). 

Compound 3 can also be prepared by the hydrogenation of 5-hydroxymethyl furfural (4) which, in turn, is obtained from hexoses following the same acid-catalyzed process described above for furfural [2]. 

Hydroxymethyl furfural is the other first generation furan derivative readily obtained from hexoses (C6 saccharides) [22]. Its role as a precursor to a large spectmm of monomers and the interest of the ensuing polymCTs constitute the topics of Chapter 6, complementary to those relative to furfural. 

The formation of furfural is an acid-catalyzed dehydration reaction in which 3 moles of water are removed from 1 mole of hexose or pentose. The reactions are shown in Fig. 3.8. A common method for producing 5-(hydroxymethyl) furfural is the reaction of sucrose described by Haworth and Jones [8] in which a 30% solution of sucrose in water is heated to 120-140°C under pressure for 2-3 hr with 0.3% oxalic acid. In this process, the 5-(hydroxymethyl) furfural is formed primarily from the fructose part of sucrose and results in a 57% yield. 

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