Promoter-Assisted Stereoselective Synthesis of the 6-Deoxy-β-d-manno-heptopyranose Oligosaccharides

Abstract

We report a promoter-assisted glycosidation approach for the stereoselective synthesis of the 6-deoxy-β-D-mannoheptopyranose oligosaccharides. SphosAuNTf 2 -promoted glycosidation of 6-deoxy-D-manno-heptopyranosyl o-hexynylbenzoate with common alcohols afforded a range of 6-deoxy-D-manno-heptosides with good to excellent β-selectivities. The counterion and the ligand of SPhosAuNTf 2 were found to have a dramatic effect on the formation of the 1,2-cis-β-linked 6-deoxy-D-manno-heptosides. This approach was effectively applied to the stereocontrolled synthesis of the 6-deoxy-β-D-manno-heptopyranose oligosaccharides relevant to Burkholderia pseudomallei and Burkholderia mallei.

Promoter-Controlled Synthesis and Antigenic Evaluation of Mannuronic Acid Alginate Glycans of Pseudomonas aeruginosa

“…Promoters could considerably affect the glycosylation outcomes, especially for the challenging glycosylation . Although gold­(I)-catalyzed glycosylation of glycosyl ( Z )-ynenoates is versatile for the synthesis of various glycans, new activation modes of glycosyl ( Z )-ynenoates are urgently required.…”