Trichloroimidate glycosylation

In another synthesis of the rat brain Thy-1 GPI anchor, Schmidt and coworkers [88] have adopted the linear strategy to construct the pentasaccharide building block. As shown in O Scheme 11, after all monosaccharide units were obtained, they were assembled sequentially by the trichloroimidate glycosylation method to form pentasaccharide 130. It was manipulated... 

Glycosylation. Protected glycosyl fluorides and trichloroimidates undergo glycosylation, whereas the correspionding glycosyl bromides and phosphates are inert. 

Glycosyl trlchloroacetimldates have been used to prepare glycosyl phosphates by treatment with mono- or dl-esters of phosphoric acid the reaction normally proceeded with predominant inversion (Scheme 3) but in the case of the trichloroimidate (15) with monocetyl phosphate retention was observed. 

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