Regio- and chemoselective manipulation under mild conditions on glucosamine derivatives for oligosaccharide synthesis and its application toward N-acetyl-d-lactosamine and Lewis X trisaccharide

Special emphasis on regio- and chemoselective manipulation on a new glucosamine scaffold was laid, toward the short-step and efficient synthetic routes for oligosaccharides. First, the blocking of two hydroxyl groups at C-1 and C-6 positions of N-protected glucosamine at once by silylation followed by an oxazolidinone formation between C-3 hydroxyl and C-2 amino groups were established, to lead an expeditious way for a glycosyl acceptor for lactosamine synthesis. Second, without any effect on acetyl protective groups in the same molecule, the ring-opening of oxazolidinone and hydrolysis of resulting carbonate under mild conditions allowed the C-3 hydroxyl group to be free, which is indispensable for further extension to oligosaccharides, such as a LeX trisaccharide.