138923-97-4

Upstream product

• 350255-13-9 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose 
• 166733-02-4 S-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)-N,N,N',N'-tetramethyl-N''-phenylphosphorodiamidimidothioate 
• 6386-24-9 2,3,4,6-tetra-O-benzyl-D-galactopyranose 
• 74925-16-9 3-O-(Trifluoromethanesulfonyl)-1,2:5,6-di-O-isopropylidene-α-D-gulofuranose 
• 38184-10-0 phenyl 2,3,4,5-tetra-O-benzyl-1-thio-β-D-glucopyranoside 

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.

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.

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