33164-03-3Relevant articles and documents
Mapping the Relationship between Glycosyl Acceptor Reactivity and Glycosylation Stereoselectivity
van der Vorm, Stefan,van Hengst, Jacob M. A.,Bakker, Marloes,Overkleeft, Herman S.,van der Marel, Gijsbert A.,Codée, Jeroen D. C.
supporting information, p. 8240 - 8244 (2018/05/03)
The reactivity of both coupling partners—the glycosyl donor and acceptor—is decisive for the outcome of a glycosylation reaction, in terms of both yield and stereoselectivity. Where the reactivity of glycosyl donors is well understood and can be controlled through manipulation of the functional/protecting-group pattern, the reactivity of glycosyl acceptor alcohols is poorly understood. We here present an operationally simple system to gauge glycosyl acceptor reactivity, which employs two conformationally locked donors with stereoselectivity that critically depends on the reactivity of the nucleophile. A wide array of acceptors was screened and their structure–reactivity/stereoselectivity relationships established. By systematically varying the protecting groups, the reactivity of glycosyl acceptors can be adjusted to attain stereoselective cis-glucosylations.
Synthesis and mass spectrometric analysis of disaccharides from methanolysis of heparan sulfate
He, Qi Qi,Trim, Paul J.,Snel, Marten F.,Hopwood, John J.,Ferro, Vito
, p. 8791 - 8803 (2018/11/30)
The quantification of heparan sulfate (HS) in biological matrices, e.g., urine, cerebrospinal fluid, tissue samples etc., is of great importance for the diagnosis and prognosis of several of the mucopolysaccharidosis (MPS) disorders, which are lysosomal storage diseases of impaired glycosaminoglycan metabolism. The development of suitable assays for this purpose is challenging due to the high molecular weight and complexity of HS. Recent efforts towards this goal include the acid catalysed methanolysis of HS, which desulfates the polymer and results in the formation of disaccharide cleavage products which can be detected and quantified by LC-MS/MS. We have synthesized a library of 12 HS-derived disaccharides as methanolysis standards via the stereoselective 1,2-cis glycosylation of suitably protected GlcA and IdoA acceptors with a 2-deoxy-2-azido thioglucoside donor. This facilitated identification of the major peaks in the LC-MS/MS chromatograms, and potentially will allow the monitoring of specific metabolites as surrogate markers for genotype. This work also paves the way towards a fully quantitative LC-MS/MS assay for HS via the preparation of a suitably labelled derivative.
A green and convenient method for regioselective mono and multiple benzoylation of diols and polyols
Zhang, Xiaoling,Ren, Bo,Ge, Jiantao,Pei, Zhichao,Dong, Hai
supporting information, p. 1005 - 1010 (2016/02/03)
An efficient method for regioselective benzoylation of diols and polyols was developed. The benzoylation is catalyzed by only 0.2 equiv of benzoate anion in acetonitrile with the addition of a stoichiometric amount of benzoic anhydride under very mild condition, leading to high yields. Compared with all other methods, this method shows particular advantage in regioselective multiple benzoylation of polyols, and in avoiding the use of any metal-based catalysts and any amine bases, which is more environment-friendly.
Regioselective mono and multiple alkylation of diols and polyols catalyzed by organotin and its applications on the synthesis of value-added carbohydrate intermediates
Xu, Hengfu,Ren, Bo,Zhao, Wei,Xin, Xiaoting,Lu, Yuchao,Pei, Yuxin,Dong, Hai,Pei, Zhichao
, p. 3490 - 3499 (2016/06/06)
A catalytic amount of dibutyltin dichloride was used to develop regioselective alkylation of diols and multiple alkylation of polyols. Alkyl groups, including allyl, alkynyl and long-chain alkyl groups, were successfully introduced to one or two hydroxyl
Selective 4,6-O-benzylidene formation of methyl α-d-mannopyranoside using 2,6-dimethylbenzaldehyde
Liotta, Louis J.,Chalmers, Jennifer F.,Falco Marshall, Jessica N.,Ferreira, Timothy E.,Mullen, Hannah E.,Pace, Nicholas J.
, p. 31 - 36 (2014/05/20)
While methyl α-d-glucopyranosides and α-d-galactopyranosides selectively form 4,6-O-benzylidenes when reacted with excess benzaldehyde in the presence of acid catalyst methyl α-d-mannopyranosides does not exhibit the same selectivity because of the cis-ar
Halide promoted organotin-mediated carbohydrate benzylation: Mechanism and application
Zhou, Yixuan,Li, Jinyang,Zhan, Yingjie,Pei, Zhichao,Dong, Hai
supporting information, p. 2693 - 2700 (2013/03/28)
In the present study, the mechanistic origin of the promoted organotin-mediated carbohydrate benzylation by halides was explored by the comparison of the activation ability of halides on benzylation of methyl β-d-galactoside. It was demonstrated that the
Enantioselective alkylation of aldehydes using dialkylzincs catalyzed by simple chiral diols derived from naturally occurring monosaccharides
Michigami, Kyosuke,Hayashi, Masahiko
supporting information, p. 4221 - 4225 (2013/06/27)
Enantioselective alkylation of aldehydes was achieved in up to 84% ee using dialkylzincs catalyzed by simple diols derived from naturally occurring monosaccharides.
Carbohydrate-derived PSE acetals: Controlled base-induced ring cleavage
Chéry, Florence,Cabianca, Elena,Tatibou?t, Arnaud,De Lucchi, Ottorino,Rollin, Patrick
experimental part, p. 544 - 551 (2012/01/14)
Retro-Michael type reactions applied to PSE acetals protecting monosaccharides led either to complete removal or to ring-cleavage. In protic medium, application of standard basic conditions resulted in acetal deprotection, while the use of butyl lithium in aprotic medium allowed controlled ring-cleavage. A regio- and stereoselective C- over O-alkylation was observed during the process. Furthermore, depending on the substrates and the reaction conditions involved, new carbohydrate-derived β-alkoxyvinyl sulfones were obtained with varying regioselectivity.
Construction of triazolyl bidentate glycoligands (TBGs) by grafting of 3-azidocoumarin to epimeric pyranoglycosides via a fluorogenic dual click reaction
Xue, Jia-Lu,He, Xiao-Peng,Yang, Jin-Wei,Shi, De-Tai,Cheng, Chao-Ying,Xie, Juan,Chen, Guo-Rong,Chen, Kaixian
, p. 38 - 42 (2013/01/15)
Glycoligands, which feature a glycoside as the central template incorporating Lewis bases as metal chelation sites and various fluorophores as the chemical reporter, represent a range of interesting scaffolds for development of chemosensors. Here, new typ
Synthesis of novel photolabile glycosides from methyl 4,6-O-(o-nitro)benzylidene-α-d-glycopyranosides
Zhu, Chen-Jiang,Yi, Hua,Chen, Guo-Rong,Xie, Juan
, p. 10687 - 10693 (2008/12/23)
Novel photolabile sugar derivatives bearing a 4- or 6-O-(o-nitro)benzyl group have been prepared from the corresponding methyl 4,6-O-(o-nitro)benzylidene α-d-glycopyranosides. Regioselective cleavage with BF3·Et2O/Et3SiH led to the methyl 6-O-(o-nitro)benzyl gluco- and manno-α-d-glycopyranosides 3 and 6. Inversion of configuration at 4-OH position of gluco and manno derivatives offered the otherwise inaccessible methyl 6-O-(o-nitro)benzyl galacto- and talo-α-d-glycopyranosides 4, 5, and 7. Careful reaction with PhBCl2/Et3SiH (3 equiv of reagents, 10 min at -78 °C) led to the desired methyl 4-O-(o-nitro)benzyl gluco- and manno-α-d-glycopyranosides 8 and 9 in very good yield. However, prolonged reaction with 6 equiv of PhBCl2/Et3SiH transformed the methyl 4,6-O-(o-nitro)benzylidene α-d-glucopyranoside 11 into the reduced d-glucitol derivative 15. Oxidative cleavage of 5,6-diol function of 15 gave the corresponding photolabile l-xylose 17. The photolabile glucosides 3 and 8 have been further transformed into the photolabile α-C-allyl d-glucopyranosides 20 and 22.
