67145-38-4

Upstream product

• 97205-08-8 methyl 2,3,4,6-tetra-O-benzyl-1-thio-β-D-galactopyranoside 
• 6386-24-9 2,3,4,6-tetra-O-benzyl-D-galactopyranose 
• 125411-99-6 ethyl 2,3,4,6-tetra-O-benzyl-1-thio-β-D-galactopyranoside 
• 53081-25-7 2,3,4,6-tetra-O-benzyl-D-galactopyranose 
• 3866-62-4 2,3,4,6-tetra-O-benzyl-D-galactopyranosyl acetate 
• 74666-83-4 S-ethyl 2,3,4,6-tetra-O-benzyl-1-deoxy-1-thio-α-D-mannopyranoside 
• 131531-70-9 4-methylphenyl 2,3,4,6-tetra-O-benzyl-1-thio-α-D-mannopyranoside 
• 4132-28-9 2,3,4,6-tetra-O-benzyl-D-mannopyranose 
• 4132-28-9 2,3,4,6-tetra-O-benzyl-α-D-mannopyranoside 

Downstream Products

• 83562-61-2 propyl O-(2,3,4,6-tetra-O-benzyl-α-D-galactopyranosyl)-(1-4)-O-(2-O-benzoyl-3,6-di-O-benzyl-β-D-galactopyranosyl)-(1-3)-2-acetamido-4,6-di-O-benzyl-2-deoxy-β-D-glucopyranoside 
• 143995-72-6 ethyl 2,3,4,6-tetra-O-benzyl-α-D-galactopyranosyl-(1->6)-2,3,4-tri-O-benzyl-1-thio-β-D-galactopyranoside 
• 1085405-94-2 allyl 2,3,4,6-tetra-O-benzyl-α-D-galactopyranosyl-(1->5)-2,3-O-isopropylidene-α-D-lyxopyranoside 
• 914102-57-1 benzoxazol-2-yl 2,3,4,6-tetra-O-benzyl-1-thio-β-D-galactopyranoside 
• 55094-26-3 methyl 2,3,4-tri-O-benzyl-6-O-(2,3,4,6-tetra-O-benzyl-α-D-galactopyranosyl)-α-D-glucopyranoside 
• 55628-54-1 3,4,6-tri-O-benzyl-D-glucal 

Relevant academic research and scientific papers

Synthesis of blood group A and B (type 2) tetrasaccharides. A strategy with fucosylation at the last stage

The traditionally used strategy for the synthesis of blood group A and B tetrasaccharides includes 2′-O-fucosylation of lactosamine followed by insertion of an α1-3 linked N-acetylgalactosamine or a galactose moiety. Here, we report the synthesis of 3-aminopropyl glycosides of A (type 2) and B (type 2) tetrasaccharides via an alternative sequence, i.e. α-galactosaminylation (or α-galactosylation) followed by α-fucosylation. This strategy allows us to synthesize fucose-free trisaccharides GalNAcα1-3Galβ1-4GlcNAc and Galα1-3Galβ1-4GlcNAc, which are promising targets for immunotherapy utilising human natural antibodies against the trisaccharides. The key stage in this scheme was the selective chloroacetylation of the 2′-OH group of βGal in the intermediate trisaccharides having the second (3-OH) unprotected group.The protocol is suitable for multigram syntheses and its further scaling up.

Bismuth(iii) triflate as a novel and efficient activator for glycosyl halides

Presented herein is the discovery that bismuth(iii) trifluoromethanesulfonate (Bi(OTf)3) is an effective catalyst for the activation of glycosyl bromides and glycosyl chlorides. The key objective for the development of this methodology is to em

Stereocontrolled α-Galactosylation under Cooperative Catalysis

A recent discovery of a cooperative catalysis comprising a silver salt and an acid led to a dramatic improvement in the way glycosyl halides are glycosidated. Excellent yields have been achieved, but the stereoselectivity achieved with 2-O-benzylated donors was poor. Reported herein is our first attempt to refine the stereoselectivity of the cooperatively catalyzed galactosylation reaction. Careful optimization of the reaction conditions along with studying effects of the remote protecting groups led to excellent stereocontrol of α-galactosylation of a variety of glycosyl acceptors with differentially protected galactosyl donors.

Synthesis of Glycosyl Chlorides and Bromides by Chelation Assisted Activation of Picolinic Esters under Mild Neutral Conditions

A general method has been developed for the formation of glycosyl chlorides and bromides from picolinic esters under mild and neutral conditions. Benchtop stable picolinic esters are activated by a copper(II) halide species to afford the corresponding products in high yields with a traceless leaving group. Rare β glycosyl chlorides are accessible via this route through neighboring group participation. Additionally, glycosyl chlorides with labile protecting groups previously not easily accessible can be prepared.

Koenigs–Knorr Glycosylation Reaction Catalyzed by Trimethylsilyl Trifluoromethanesulfonate

The discovery that traditional silver(I)-oxide-promoted glycosidations of glycosyl bromides (Koenigs–Knorr reaction) can be greatly accelerated in the presence of catalytic trimethylsilyl trifluoromethanesulfonate (TMSOTf) is reported. The reaction conditions are very mild that allowed for maintaining a practically neutral pH and, at the same time, providing high rates and excellent glycosylation yields. In addition, unusual reactivity trends among a series of differentially protected glycosyl bromides were documented. In particular, benzoylated α-bromides were much more reactive than their benzylated counterparts under these conditions.

Regenerative Glycosylation

Previously, we communicated 3,3-difluoroxindole (HOFox)-mediated glycosylations wherein 3,3-difluoro-3H-indol-2-yl (OFox) imidates were found to be key intermediates. Both the in situ synthesis from the corresponding glycosyl bromides and activation of the OFox imidates could be conducted in a regenerative fashion. Herein, we extend this study to the synthesis of various glycosidic linkages using different sugar series. The main outcome of this study relates to enhanced yields and/or reduced reaction times of glycosylations. The effect of HOFox-mediated reactions is particularly pronounced in case of unreactive glycosyl donors and/or glycosyl acceptors. A multistep regenerative synthesis of oligosaccharides is also reported.

Pyranoside-into-Furanoside Rearrangement of 4-Pentenyl Glycosides in the Synthesis of a Tetrasaccharide-Related to Galactan I of Klebsiella pneumoniae

An efficient strategy for synthesis of a spacer-armed tetrasaccharide related to galactan I of Klebsiella pneumoniae is described, which uses newly developed acid-free conditions for the pyranoside-into-furanoside (PIF) rearrangement of a digalactoside bearing a 4-pentenyl group at the anomeric position. The 4-pentenyl aglycon was successfully used both as a leaving group in the glycosylation of 3-(trifluoroacetamido)propanol, and as a temporary anomeric protecting group, allowing conversion into an imidate donor. Regioselective coupling of the disaccharide blocks gave the desired tetrasaccharide sequence required for investigation of the interaction of galactan I with immune-system proteins.

GLYCOMIMETIC INHIBITORS OF PA-IL AND PA-IIL LECTINS

Compounds, compositions, and methods for the diagnosis and/or treaimeni of medical conditions involving infections with and colonization by Fseudomonas bacteria including, for example, Fseudomonas aeruginosa in the lungs of patients with cystic fibrosis are described.

Regenerative glycosylation under nucleophilic catalysis

This article describes 3,3-difluoroxindole (HOFox)-mediated glycosylation. The uniqueness of this approach is that both the in situ synthesis of 3,3-difluoro-3H-indol-2-yl (OFox) glycosyl donors and activation thereof can be conducted in a regenerative fashion as is a typical reaction performed under nucleophilic catalysis. Only a catalytic amount of the OFox imidate donor and a Lewis acid activator are present in the reaction medium. The OFox imidate donor is constantly regenerated upon its consumption until glycosyl acceptor has reacted.

Synthesis of glycosyl fluorides from thio-, seleno-, and telluroglycosides and glycosyl sulfoxides using aminodifluorosulfinium tetrafluoroborates

Glycosyl fluorides can be synthesized from thio-, seleno-, and telluroglycosides and glycosyl sulfoxides using the aminodifluorosulfinium tetrafluoroborate reagents Xtalfluor-E and -M, with or without added N-bromosuccinimide. Mechanistic studies provide evidence that fluoride is delivered from the tetrafluoroborate counterion.