152983-24-9

Upstream product

• 71676-30-7 phenyl 4,6-di-O-benzylidene-1-thio-β-D-galactopyranoside 
• 108-24-7 acetic anhydride 
• 75-36-5 acetyl chloride 
• 13992-16-0 1-deoxy-1-(phenylthio)-2,3,4,6-tetra-O-acetyl-β-D-galactopyranose 
• 1125-88-8 benzaldehyde dimethyl acetal 
• 108-98-5 thiophenol 
• 16758-34-2 1-thiophenyl-β-D-galactopyranoside 
• 64-19-7 acetic acid 
• 25878-60-8 D-galactose pentaacetate 

Downstream Products

• 146933-98-4 2,3-Di-O-acetyl-4,6-O-benzylidene-β-D-galactopyranosyl phenyl sulfone 
• 208644-68-2 phenyl 2,3-di-O-acetyl-1-thio-β-D-galactopyranoside 
• 869715-01-5 benzyloxycarbonylmethyl 2,3-di-O-acetyl-4,6-O-benzylidene-β-D-galactopyranoside 
• 887699-85-6 1-S-phenyl 2,3-di-O-acetyl-4,6-O-[1-cyano-2-(2-iodophenyl)]ethylidene-β-D-galactopyranoside 
• 887699-86-7 1-S-phenyl 2,3-di-O-benzoyl-4,6-O-[1-cyano-2-(2-iodophenyl)]ethylidene-β-D-galactopyranoside 
• 887699-87-8 1-adamantanyl 2,3-di-O-benzoyl-4,6-O-[1-cyano-2-(2-iodophenyl)]ethylidene-β-D-galactopyranoside 
• 887699-93-6 methyl 4-O-(2,3-di-O-benzoyl-4,6-O-[1-cyano-2-(2-iodophenyl)]ethylidene-β-D-galactopyranosyl)-2,3-O-isopropylidene-α-L-rhamnopyranoside 
• 887699-94-7 methyl 2,3,4-tri-O-benzyl-6-O-(2,3-di-O-benzoyl-4,6-O-[1-cyano-2-(2-iodophenyl)]ethylidene-β-D-galactopyranosyl)-α-D-glucopyranoside 

Relevant academic research and scientific papers

N -Glycosylation with sulfoxide donors for the synthesis of peptidonucleosides

The synthesis of glycopyranosyl nucleosides modified in the sugar moiety has been less frequently explored, notably because of the lack of a reliable method to glycosylate pyrimidine bases. Herein we report a solution in the context of the synthesis of peptidonucleosides. They were obtained after glycosylation of different pyrimidine nucleobases with glucopyranosyl donors carrying an azide group at the C4 position. A methodological study involving different anomeric leaving groups (acetate, phenylsulfoxide and ortho-hexynylbenzoate) showed that a sulfoxide donor in combination with trimethylsilyl triflate as the promoter led to the best yields.

Studies towards the total synthesis of repeating unit of O-sulfated polysaccharide from marine bacterium Cobetia pacifica KMM 3878

Herein we report assembly of the appropriately protected trisaccharide repeating unit of Cobetia pacifica KMM 3878 O-sulfated polysaccharide. Our synthesis involves 3,4-O-pyruvilated galactose as the key building block which acts as a donor as well as acceptor in the construction of trisaccharide. We obtained the R isomer as a major stereoisomer in the pyruvilation reaction. The glycosylations proceeded with high stereo and regioselectivity.

S-Adamantyl Group Directed Site-Selective Acylation: Applications in Streamlined Assembly of Oligosaccharides

The site-selective functionalization of carbohydrates is an active area of research. Reported here is the surprising observation that the sterically encumbered adamantyl group directed site-selective acylation at the C2 position of S-glycosides through dispersion interactions between the adamantyl C?H bonds and the π system of the cationic acylated catalyst, which may have broad implications in many other chemical reactions. Because of their stability, chemical orthogonality, and ease of activation for glycosylation, the site-selective acylation of S-glycosides streamlines oligosaccharide synthesis and will have wide applications in complex carbohydrate synthesis.

Diazepinium perchlorate: a neutral catalyst for mild, solvent-free acetylation of carbohydrates and other substances

Diazepinium perchlorate, an essentially neutral organic salt possessing excellent stability, has been found to be well suited for the acetylation of free as well as partially protected sugars, phenols, thiophenols, thiols and other alcohols as well as amines. The diazepinium perchlorate-catalyzed acetylation is mild, organic and solvent-free and leaves acid sensitive protecting groups such as TBDMS/TBDPS/Tr ethers and isopropylidene/benzylidene acetals present on a substrate unaffected. Regioselective hydroxyl protection in partially protected carbohydrate derivatives/polyhydroxylic compounds was possible and was proved to be a convenient time-saving alternative to the conventional synthesis of such compounds. Easy preparation of the catalyst, mild reaction conditions and an environmentally benign protocol are some of the notable features of this reaction. The results obtained on the acetylation of phenols and thiophenols could be rationalized through their local nucleophilicity index obtained from DFT calculations.

DABCO: An efficient promoter for the acetylation of carbohydrates and other substances under solvent-free conditions

A simple, mild and efficient solvent-free method for the acetylation of carbohydrates, and their partially protected derivatives, as well as non-carbohydrate substances in excellent yields in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) is described with the advantage of tolerance to various functional groups, short reaction time and ease of product isolation.

Acylation of carbohydrates over Al2O3: Preparation of partially and fully acylated carbohydrate derivatives and acetylated glycosyl chlorides

Selective and per-O-acylation of carbohydrate derivatives using acyl chlorides and Al2O3, a solid support reagent, is reported. This protocol does not require the addition of any base or activator. This methodology has been further extended to the selective acylation of carbohydrate diols and the one-pot preparation of acetylated glycosyl chlorides direct from free reducing sugars. The yields obtained in most of the cases are excellent.

A facile synthesis of the GalNAcβ1→4Gal target sequence of respiratory pathogens

The carbohydrate sequence, GalNAcβ1→4Gal, is the target for the adhesion of several respiratory pathogens. The sequence was prepared in an optimized synthesis in forms that allow conjugation to scaffolds or surfaces.

Chemical synthesis of (4,6-Pyr)-Gal β1→4GlcNacβ1→3Fucβ1→OMe: A pyruvated trisaccharide related to the cell aggregation of the sponge Microciona prolifera

4,6-O-[(R)-1-carboxylethylidene] Galβ1→4GlcNAcβ1→3Fucβ1→OMe, a pyruvated trisaccharide unit involved in the aggregation factor of the marine sponge Microciona prolifera, was synthesized stereospecifically and unambiguously employing thioglycosides as glycosyl donors to construct glycosidic bonds.

SmI2-promoted chemistry at the anomeric center of carbohydrates. Reductive formation and reaction of glycosyl samarium (III) reagents

Reaction of 3,4,6-tri-O-benzyl-2-deoxy-α-D-arabino-hexopyranosyl chloride at room temperature with the efficient single electron transfer system of SmI2-THF-HMPA, in the presence of cyclopentanone (Barbier conditions) gave selectively the corresponding α-C-glycoside in 70percent yield.It is postulated that the reactive transient intermediate is a chiral anomeric organosamarium (III) species.Lower yields were obtained in the presence of aldehydes, such as n-butanal or isobutanal.It is also demonstrated that glycosyl phenyl sulfones undergo reductive samariation. 2,3,4,6-Tetra-O-benzyl-β-D-glucopyranosyl phenyl sulfone reacted with cyclopentanone, in the presence of SmI2-THF-HMPA, to give the corresponding β-C-glycoside selectively in 25percent yield, together with the elimination product (40percent).When the protecting group at C-2 was an acetate, a very fast β-elimination of the organosamarium intermediate occurred to give a practically quantitative yield of a substituted glycal.This work constitutes the first application of samarium(II) iodide to the reductive metallation of the anomeric center of carbohydrates.Key words: samarium diiodide / sulfones / carbohydrates / glycals / C-glycosides