Efficient Piancatelli rearrangements of HMF derivatives under microwave activation or subcritical water conditions to produce functionalized hydroxylated cyclopentenones

HMF (5-hydroxymethylfurfural), a renewable raw material from biomass, was used as starting material to provide 5-aryl-4-hydroxymethyl-4-hydroxycyclopentenones with functionalized aryl groups. In a first time, arylic substituents were added to the...