56822-55-0Relevant academic research and scientific papers
A 1,2-trans-Selective Glycosyl Donor Bearing Cyclic Protection at the C-2 and C-3 Hydroxy Groups
Yagami, Nahoko,Tamai, Hideki,Udagawa, Taro,Ueki, Akiharu,Konishi, Miku,Imamura, Akihiro,Ishida, Hideharu,Kiso, Makoto,Ando, Hiromune
supporting information, p. 4778 - 4785 (2017/09/07)
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
Vankayalapati, Hariprasad,Singh, Gurdial,Tranoy, Isabelle
, p. 1373 - 1381 (2007/10/03)
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
Tsvetkov, Yury E.,Klotz, Wolfgang,Schmidt, Richard R.
, p. 371 - 376 (2007/10/02)
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
Stereoselective synthesis of α-linked saccharides by use of per O-benzylated 2-pyridyl 1-thio hexopyranosides as glycosyl donors and methyl iodide as an activator
Mereyala,Reddy
, p. 6435 - 6448 (2007/10/02)
A new, practical, stereoselective glycosidation methodology is described where per O-benzylated 2-pyridyl 1-thio-α/β-hexopyranosyl donors of D-gluco-(1), D-galacto- (2), D-manno- (3) and L-rhamno- (4) configurations have been efficiently coupled with dive
An extremely mild and general method for the stereocontrolled construction of 1,2-cis-glycosidic linkages via S-glycopyranosyl phosphorodiamidimidothioates
Hashimoto, Shun-Ichi,Honda, Takeshi,Ikegami, Shiro
, p. 4769 - 4772 (2007/10/02)
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
A MILD GENERAL METHOD FOR THE SYNTHESIS OF α-LINKED DISACCHARIDES
Reddy, G. Venugopal,Kulkarni, Vinayak R.,Mereyala, Hari Babu
, p. 4283 - 4286 (2007/10/02)
Stereoselective α-glycosylations may be achieved using stable 2-pyridyl thioglycosides (anomeric mixture) having a non-participating 2-substituent as glycosyl donor and methyl iodide as an activator.
