The Stereoselectivity of Neighboring Group-Directed Glycosylation Is Concentration-Dependent.

ABSTRACT: The formation of 1,2-trans-glycosides taking advantage of neighboring group participation by stereodirecting esters at the 2-position of glycosyl donors is widely held to be a robust and reliable protocol. Examples abound, however, of cases in which less-than-perfect selectivity is obtained, causing practitioners to survey different esters or resort to alternative strategies in the quest for optimal selectivities and yields. Consideration of the mechanism of neighboring group participation and in particular of the competing process of S_N2-like glycosylation with activated covalent donors leads to the hypothesis that in cases of imperfect selectivity, more careful attention to reaction concentration and stoichiometry may be beneficial. Three case studies are presented to d

SUBMITTER: Basu P 

PROVIDER: S-EPMC11848824 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature