Fw. Lichtenthaler et al., Sugar-derived building blocks. Part 26. Hydrophilic pyrroles, pyridazines and diazepinones from D-fructose and isomaltulose, GREEN CHEM, 3(5), 2001, pp. 201-209
Efficient, large scale-adaptable protocols are described for the straightfo
rward conversion of D-fructose-derived 5-hydroxymethylfurfural (HMF) and of
5-glucosyloxymethylfurfural (alpha GMF, from isomaltulose) into hydrophili
cally substituted N-heterocycles of the pyrrole, pyridazine, thiophene and
benzodiazepine type. Key intermediates are 1,6-dihydroxy-2,5-hexenediones,
readily generated by oxidative furan ring-opening.