64694-22-0Relevant articles and documents
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.
Dichloro-cyanoacetimidates as glycosyl donors
Schmelzer, Uwe,Zhang, Zhaojun,Schmidt, Richard R.
, p. 223 - 238 (2008/02/12)
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
Grayson, Elizabeth J.,Ward, Sarah J.,Hall, Alison L.,Rendle, Phillip M.,Gamblin, David P.,Batsanov, Andrei S.,Davis, Benjamin G.
, p. 9740 - 9754 (2007/10/03)
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.
