345209-46-3

Upstream product

• 53008-65-4 methyl 2,3,4-tri-O-benzyl-D-glucopyranoside 
• 144002-21-1 dibenzyl (methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-β-D-galacto-2-nonulopyranosidonate) phosphite 
• 145240-79-5 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-1-(methoxycarbonyl)-D-glycero-α-D-galacto-2-nonulopyranosyl diethyl phosphite 
• 118977-25-6 methyl (phenyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-thio-D-glycerol-β-D-galactonon-2-ulopyranoside)onate 
• 20298-34-4 methyl (5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-β-D-glycero-D-galacto-2-nonulopyranosyl)onate 

Relevant academic research and scientific papers

An effective sialylation method using N-Troc- and N-Fmoc-protected β-thiophenyl sialosides and application to the one-pot two-step synthesis of 2,6-sialyl-T antigen

We describe an efficient sialylation method using β-thiosialosides with various N-protecting groups. Modification of the C-5 amino group of β-thiosialosides into N-Fmoc and N-Troc derivatives enhanced their reactivity in glycosidation. In addition, a minimum amount of MS-3 A? was effective to improve the yield of α-linked sialoside. Branched type one-pot glycosylation initiating glycosidation of the N-Troc-protected β-thiophenyl sialoside at a primary alcohol provided the protected 2,6-sialyl-T antigen in good yield, which was converted to the fully deprotected glycosyl amino acid.

Glycosyl Phosphites as Glycosylation Reagents: Scope and Mechanism

The glycosylation reactions with glycosyl phosphites in the presence of catalytic amounts of TMSOTf at low temperature have been studied with different donors and acceptors for the synthesis of several glycosides, including O-glycosides, S-glycosides, C-glycosides, and glycopeptides.Mechanistic investigations of the reactions indicate that the glycosyl phosphite is activated by either TfOH or TMSOTf, depending on how the substrates are mixed.When the acceptor is treated with TMSOTf first, the glycosyl phosphite is activated by the resulting TfOH.The glycosyl phosphite can also be activated by TMSOTf directly.The best result is, however, to mix the acceptor and TMSOTf first, followed by addition of the glycosyl phosphite.

Efficient sialylation with phosphite as leaving group

The search for an acid labile leaving group attached to the anomeric position of O-protected N-acetylneuraminic acid led to phosphite derivative 1c which provided in the presence of catalytic amounts of trimethylsilyl trifluoromethanesulfonate the desired