Building blocks from sugars. Part 23. Hydrophilic 3-pyridinols from fructose and isomaltulose

Article abstract of DOI:10.1016/S0040-4020(98)00634-6

Brief exposure to bromine in water-methanol at 0 °C smoothly and effectively converts furfurylamines with hydroxymethyl (5) or glucosyloxymethyl substituents (16) into the respective 6-substituted 3- pyridinols 9 and 19, whereas the N-methyl-furfurylamines 10 and 17 elaborate the N-methyl-pyridinium betaines 13 and 22. Combination of this multistep one-pot reaction with the large scale-feasible generation of hydroxymethylfurfural (4) from D-fructose and its O-glucosyl analog 15 from isomaltulose, together with their ready conversion into furfurylamines by reductive amination, opens up a preparatively satisfactory, 3-step 'reaction channel' from inexpensive sugars to hydrophilic 3-pyridinols, of interest as intermediate chemicals for drugs of the pyridostigmine type and agrochemicals.