Preactivation-Based Reactivity-Independent One-Pot Glycosylation

SCHEME 6.23 Preactivation-based one-pot synthesis of the hyaluronic acid trisaccharide 

SCHEME 6.24 Huang and Ye s preactivation-based one-pot synthesis of oligosaccharides. 

SCHEME 6.28 Mong s stereoselective one-pot synthesis using DMF as the novel additive to facilitate the 1,2-as-glycoside formation, (a) The glycosyl imidates formed with DMF. (b) The one-pot synthesis of trisaccharide 142. 

Various innovative methodologies to carry out one-pot glycosylation from the nonreducing end to the reducing end have been discussed thus far. Alternatively, one-pot synthesis can be performed from the reducing end to the nonreducing end, which requires differentiation of the inherent reactivities of various hydroxy groups. For 

SCHEME 6.30 HC104-silica-promoted one-pot synthesis of trisaccharide 152. 

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