138902-22-4

Upstream product

• 350255-13-9 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose 
• 55951-90-1 1,2:5,6-di-O-isopropylidene-3-O-trifluoromethanesulfonyl-α-D-allofuranose 
• 6386-24-9 2,3,4,6-tetra-O-benzyl-D-galactopyranose 
• 3866-62-4 2,3,4,6-tetra-O-benzyl-D-galactopyranosyl acetate 
• 947335-88-8 O-(2,3,4,6-tetra-O-benzyl-α-D-galactopyranosyl) dichloro-cyanoacetimidate 
• 582-52-5 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose 
• 870472-11-0 ethyl 2,3,4,6-tetra-O-benzyl-β-D-galactopyranosyl disulfide 
• 53008-62-1 2,3,4,6-tetra-O-benzyl-α-D-galactopyranosyl iodide 
• 38184-10-0 phenyl 2,3,4,5-tetra-O-benzyl-1-thio-β-D-glucopyranoside 
• 166733-02-4 S-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)-N,N,N',N'-tetramethyl-N''-phenylphosphorodiamidimidothioate 

Relevant academic research and scientific papers

A 1,2-trans-Selective Glycosyl Donor Bearing Cyclic Protection at the C-2 and C-3 Hydroxy Groups

A new 1,2-trans-selective glycosylation reaction is described. Glucosyl donors protected cyclically at the C-2 and C-3 hydroxy groups as six- (butane diacetal), seven- (tetraisopropyldisiloxanylidene), or eight- (2,3-o-xylylene) membered fused rings were synthesized in a straightforward manner. The glycosylation reactions of the glucosyl donors with various acceptors mainly generated β-glycosides under conventional reaction conditions. The results show that the o-xylylene group is a suitable 1,2-trans-directing group from the points of view of stereoselectivity and chemical stability. A conformational study of the oxocarbenium ion of an o-xylylene-protected glucose derivative by NMR spectroscopy and computational simulation was carried out. The results imply that the oxocarbenium ion mainly adopts a 4H3 conformation owing to the rigid trans-fused ring at C-2 and C-3, while a noncyclically protected derivative might fluctuate between conformations. These results suggest that an eclipsing interaction between the pseudoequatorial xyloxy group at C-2 and the incoming nucleophile hampers 1,2-cis attack.

Dichloro-cyanoacetimidates as glycosyl donors

Transformation of 1-O-unprotected glucose and galactose derivatives (1a-d) into O-glycosyl dichloro-cyanoacetimidates (2a-d) was performed with dichloro-cyanoacetonitrile in the presence of DBU as base. Reaction with different acceptors (3a-d) under TMSOT

Glycosyl disulfides: Novel glycosylating reagents with flexible aglycon alteration

Glycosyl disulfides have been shown for the first time to be effective glycosyl donors. Glucosylation and galactosylation of a panel of representative alcohol acceptors allowed the formation of 28 simple glycosides, disaccharides, and glycoamino acids in yields of up to 90%. As well as providing a novel class of effective glycosyl donors, the ability to easily alter the nature of the aglycon and the ability to differently activate donors that differ only in their aglycon simply through altering conditions lends glycosyl disulfide donors to their use in latent-active reactivity tuning strategies.

Stereoselective O-glycosylation reactions using glycosyl donors with diphenylphosphinate and propane-1,3-diyl phosphate leaving groups

Glycosyl donors having a diphenylphosphinate and a propane-1,3-diyl phosphate leaving group were easily prepared by the addition of the anomeric hydroxyl group of 2,3,4,6-tetra-O-benzyl-α,β-D-glucopyranose to diphenylphosphinic and propane-1,3- diyldioxyphosphoryl chlorides. These glycosyl donors were selectively glycosylated with a number of primary and secondary oxygen nucleophiles in the presence of trimethylsilyl triflate (TMSOTf). The use of 1,3-diyl phosphate resulted in the stereoselective formation of β-O-linked glycosides.

Glycosyl iodides are highly efficient donors under neutral conditions

Glycosyl iodides have been prepared and subjected to glycosylation under neutral conditions. The reactions are highly efficient, giving α glycosides even with sterically demanding glycosyl acceptors. Glucosyl iodides react with allyl alcohol slowest and require refluxing conditions. Galactosyl iodides are intermediate in reactivity, providing the allyl glycoside in 3 h at room temperature, whereas glycosylation of fucosyl iodides occurs in less than 1 h under similar conditions. The scope and limitations of the reactions were demonstrated with a variety of acceptors, including an anomeric hydroxyl group, to give trehalose analogs. β-Selective glycosylation of glucosyl iodides, in the absence of C-2 participation, could be achieved by simply changing the solvent from benzene to acetonitrile. Copyright (C) 1999 Elsevier Science Ltd.

Anomeric O-Alkylation, 9. Disaccharide Synthesis via Anomeric O-Alkylation

Base-promoted reaction of tetra-O-benzyl-glucose 1a with secondary alkyl trifluoromethanesulfonates 2 and 3 in toluene provides in the presence of 15-crown-5 preferentially β-glycosides 2aβ and 3aβ, respectively, in high yields.For reactions carried out a

An extremely mild and general method for the stereocontrolled construction of 1,2-cis-glycosidic linkages via S-glycopyranosyl phosphorodiamidimidothioates

A highly stereocontrolled construction of 1,2-cis-glycosidic linkages under extremely mild reaction conditions has been developed by using S-glycopyranosyl N,N,N′,N′-tetramethyl-N-phenylphosphorodiamidimidothioates with a non-participating O-2-benzyl grou