A 4-deoxy-4-fluoro analog of D-glucosamine, supplied as the hydrochloride salt for improved handling and aqueous solubility. The C4 hydroxyl is replaced by a fluorine, providing a stable, isosteric mimic that serves as a probe and metabolic inhibitor of glucosamine-processing enzymes and of hexosamine biosynthesis pathway intermediates, with utility in ¹⁹F NMR studies of glycan-protein interactions.