Oligosaccharide synthesis with trichloroacetimidates disaccharides

For the synthesis of HA oligosaccharides, model glycosylations were carried out in solution and on PEG support. A glucosamine acceptor coupled with hydrojyl-terminated PEG monomethyl ether 11 was efficiently glycosylated with trichloroacetimidate donor 10 afford an orthogonally protected disaccharide 12 which can be used for the synthesis of HA sequences, see Scheme 3. 

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