Dehydration and cyclization of α-, β-dihydroxy carbonyl compounds to 2-substituted furan derivatives

Abstract

Processes are disclosed for the synthesis of 2-substituted furan derivatives, such as furan dicarboxylic acid (FDCA), from a starting compound or substrate having a carbonyl functional group (C═O), with hydroxy-substituted carbon atoms at alpha (α) and beta (β) positions, relative to the carbonyl functional group. According a particular embodiment, an α-, β-dihydroxy carboxylate is dehydrated to form a dicarbonyl intermediate by transformation of the α-hydroxy group to a second carbonyl group and removal of the β-hydroxy group. The dicarbonyl intermediate undergoes cyclization and dehydration, to produce the 2-substituted furan derivative. Optionally, a further step of oxidation may be carried out, for example to convert a hydroxymethyl group, as a 5-substituted about the furan ring, to a carboxy group of FDCA.