Stereoselective glycosylations using donor

Takeuchi K, Tamura T, Mukaiyama T. The trityl tetrakis(penta-fluorophenyl)borate catalyzed stereoselective glycosylation using new glycosyl donor, 3,4,6-tri-0-benzyl-2-0-/j-toluoyl-beta-D-glucopyranosyl phenylcarbonate. Chem. Lett. 2000 2 122-123. 

Takeuchi, K, Mukaiyama, T, Trityl tetrakis(pentafluorophenyl)borate catalyzed stereoselective glycosylation using glycopyranosyl fluoride as a glycosyl donor, Chem. Lett, 555-556, 1998. 

To achieve the synthesis of the branched tetrasaccharide 11, a further building block fucosyl donor 12 was chosen, which promised a highly stereoselective glycosylation outcome. By using the benzoyl galactosyl... 

A novel strategy for stereoselective glycosylations has been reported in which a chiral auxiliary at the 2-position of a glycosyl donor is used (Scheme 126).189 Upon formation of an oxonium ion, participation of the nucleophilic moiety of the auxiliary is (g) selective and depedent on the chirality. 

On the other hand, Roush and coworkers reported the synthesis of the functionalized C-D-E trisaccharide precursor of Olivomycin A, in which, particularly, the 2-deoxy-2-iodo-3-methyl-Q -L-mannop)Tanosyl linkage was stereoselectively introduced by using the glycosyl acetate donor (O Scheme 26) [34], This new a-glycosylation protocol was applied to the synthesis... 

---