406488-01-5

Upstream product

• 194410-25-8 9-O-acetyl-4,8-anhydro-5,6,7-tri-O-benzyl-1,2,3-trideoxy-D-glycero-D-galacto-non-1-enitol 
• 617-04-9 (2R,3S,4S,5S,6S)-2-(hydroxymethyl)-6-methoxytetrahydro-2H-pyran-3,4,5-triol 
• 3879-79-6 (2R,3R,4S,5S,6S)-3,4,5-tris(benzyloxy)-2-((benzyloxy)methyl)-6-methoxytetrahydro-2H-pyran 
• 82659-59-4 3-(2,3,4,6-tetra-O-benzyl-α-D-mannopyranosyl)propene 

Downstream Products

• 499139-88-7 8-O-acetyl-3,7-anhydro-4,5,6-tri-O-benzyl-2-deoxy-D-glycero-D-galacto-octonic acid 

Relevant academic research and scientific papers

Synthesis of Rare 6-Deoxy- d -/ l -Heptopyranosyl Fluorides: Assembly of a Hexasaccharide Corresponding to Campylobacter jejuni Strain CG8486 Capsular Polysaccharide

Campylobacter jejuni is the leading cause of human diarrheal diseases and has been designated as one of highly resistant pathogens by the World Health Organization. The C. jejuni capsular polysaccharides feature broad existence of uncommon 6dHepp residues and have proven to be potential antigens to develop innovative antibacterial glycoconjugation vaccines. To address the lack of synthetic methods for rare 6dHepp architectures of importance, we herein describe a novel and efficient approach for the preparation of uncommon d-/l-6dHepp fluorides that have power as glycosylating agents. The synthesis is achieved by a C1-to-C5 switch strategy relying on radical decarboxylative fluorination of uronic acids arising from readily available allyl d-C-glycosides. To further showcase the application of this protocol, a structurally unique hexasaccharide composed of →3)-β-d-6didoHepp-(1→4)-β-d-GlcpNAc-(1→ units, corresponding to the capsular polysaccharide of C. jejuni strain CG8486 has been assembled for the first time. The assembly is characterized by highly efficient construction of the synthetically challenging β-(1,2-cis)-d-ido-heptopyranoside by inversion of the C2 configuration of β-(1,2-trans)-d-gulo-heptopyranoside, which is conveniently obtained by anchimerically assisted stereoselective glycosylation of the orthogonally protected 6dgulHepp fluoride. Ready accessibility of 6dHepp fluorides and the resulting glycans could serve as a rational starting point for the further development of synthetic vaccines fighting Campylobacter infection.

Epimerization of 2'-carbonylalkyl-C-glycosides via enolation, beta-elimination and intramolecular cycloaddition.

Treatment of 2'-carbonyl-alpha-C-glycopyranosides of gluco, galacto, manno, 2-deoxy, and 2-azido sugars with 4% NaOMe resulted in anomeric epimerization to give their respective beta-anomers in good to excellent yields. The epimerization of the 2'-aldehyd

Synthesis of 3-C-(6-O-acetyl-2,3,4-tri-O-benzyl-α-D-mannopyranosyl)-1-propene: A caveat

During the preparation of 3-C-(6-O-acetyl-2,3,4-tri-O-benzyl-α-D-mannopyranosyl)-1-propene, using a published Sakurai-type reaction on the parent methyl glycoside, some observations were made on the sensitivity to reaction conditions that were not previously reported. This Note presents the study of this allylation reaction followed by acetolysis, which ultimately led to the best conditions to obtain the C-glycoside, and on further transformations to yield the corresponding aldehydic and acidic derivatives.