An expedient route to acylated glucosyl halides with a free 2-OH group

摘要: Abstract The carbonyl group of 3,4,6-tri-O-benzoyl-α- d -arabino-hexosyl-2-ulose bromide (8), readily accessible from the hydroxyglycal ester, can be reduced by cyanoborohydride without affecting anomeric bromine; exclusive axial attack hydride affords benzoylated glucosyl 6 with a free 2-OH (72%). This amounts to five-step synthesis -glucose, chromatography, in 55% overall yield. Bromide 6, or more reactive α-iodide 7, smoothly generated halogen exchange, undergoes α- β-slective glycosidations, emphasizing their potential as glycosyl donors for generation (1 → 2)-linked oligosaccharides.