138923-10-1Relevant articles and documents
One-Pot Protection Strategy of Glucosamine to Assemble Building Blocks of Chitosan and Lipid A
Chen, Jyun-Siao,Huang, Po-Hsun,Lin, Yi-Jyun,Liu, Jen-Wei,Liu, Yu-Hao,Luo, Shun-Yuan,Pantawane, Amit Ravindra,Sankar, Arumugam,Wu, Hsin-Ru
, (2020/08/21)
This investigation describes a one-pot reaction to prepare a series of building blocks for glycosylation reactions, such as 3-alcohol glucosamines, fully protected glucosamines, O-4 and O-6 alcohol glucosamines. These reactions readily produce not only gl
Phosphotungstic acid as a novel acidic catalyst for carbohydrate protection and glycosylation
Chen, Jyun-Siao,Sankar, Arumugam,Lin, Yi-Jyun,Huang, Po-Hsun,Liao, Chih-Hsiang,Wu, Shen-Shen,Wu, Hsin-Ru,Luo, Shun-Yuan
, p. 33853 - 33862 (2019/11/11)
This work demonstrates the utilization of phosphotungstic acid (PTA) as a novel acidic catalyst for carbohydrate reactions, such as per-O-acetylation, regioselective O-4,6 benzylidene acetal formation, regioselective O-4 ring-opening, and glycosylation. These reactions are basic and salient during the synthesis of carbohydrate-based bioactive oligomers. Phosphotungstic acid's high acidity and eco-friendly character make it a tempting alternative to corrosive homogeneous acids. The various homogenous acid catalysts were replaced by the phosphotungstic acid solely for different carbohydrate reactions. It can be widely used as a catalyst for organic reactions as it is thermally stable and easy to handle. In our work, the reactions are operated smoothly under ambient conditions; the temperature varies from 0 °C to room temperature. Good to excellent yields were obtained in all four kinds of reactions.
Formal Synthesis of Anticoagulant Drug Fondaparinux Sodium
Dai, Xiang,Liu, Wentao,Zhou, Qilong,Cheng, Chunwei,Yang, Chao,Wang, Shuqing,Zhang, Min,Tang, Pei,Song, Hao,Zhang, Dan,Qin, Yong
, p. 162 - 184 (2016/01/15)
The practical formal synthesis of the anticoagulant drug fondaparinux sodium 1 was accomplished using an optimized modular synthetic strategy. The important pentasaccharide 2, a precursor for the synthesis of fondaparinux sodium, was synthesized on a 10 g scale in 14 collective steps with 3.5% overall yield from well-functionalized monosaccharide building blocks. The strategy involved a convergent [3 + 2] coupling approach, with excellent stereoselectivity in every step of glycosylation from the monosaccharide building blocks. Efficient routes to the syntheses of these fully functionalized building blocks were developed, minimizing oligosaccharide stage functional-group modifications. The syntheses of all building blocks avoided rigorous reaction conditions and the use of expensive reagents. In addition, common intermediates and a series of one-pot reactions were employed to enhance synthetic efficiency, improving the yield considerably. In the monosaccharide-to-oligosaccharide assembly reactions, cheaper activators (e.g., NIS/TfOH, TESOTf, and TfOH) were used to facilitate highly efficient glycosylations. Furthermore, crystallization of several monosaccharide and oligosaccharide intermediates significantly simplified purification procedures, which would be greatly beneficial to the scalable synthesis of fondaparinux sodium.
Az-a colourful azulene-derived protecting group
Timmer, Mattie S.M.,Stocker, Bridget L.,Northcote, Peter T.,Burkett, Brendan A.
supporting information; experimental part, p. 7199 - 7204 (2010/03/01)
Azulen-1-yl-dicarbonyl (Az) is a novel, coloured, protecting group used to mask primary and secondary alcohols. In particular, the use of Az in the construction of carbohydrates, where a number of orthogonal protecting groups are typically required, is of
Synthesis of DTPA-conjugated (1,4)-linked 2-aminoglycosides varying in the anomeric configuration and their MRI contrast effect
Tanaka, Hiroshi,Ando, Yoshio,Wada, Masatoshi,Takahashi, Takashi
, p. 3311 - 3328 (2007/10/03)
We describe the efficient synthesis of DTPA-conjugated oligosaccharides composed of α- and/ or β-linked tri to monoglucosamines. Gd(III) complex with DTPA-conjugated chitotriitol 1 has been reported to be an effective MRI contrast agent. In order to eluci
Design and synthesis of inositolphosphoglycan putative insulin mediators
Lopez-Prados, Javier,Cuevas, Felix,Reichardt, Niels-Christian,De Paz, Jose-Luis,Morales, Ezequiel Q.,Martin-Lomas, Manuel
, p. 764 - 786 (2007/10/03)
The binding modes of a series of molecules, containing the glucosamine (1→6) myo-inositol structural motif, into the ATP binding site of the catalytic subunit of cAMP-dependent protein kinase (PKA) have been analysed using molecular docking. These calcula
Modular synthesis of heparin oligosaccharides
Orgueira, Hernan A.,Bartolozzi, Alessandra,Schell, Peter,Litjens, Remy E. J. N.,Palmacci, Emma R.,Seeberger, Peter H.
, p. 140 - 169 (2007/10/03)
A general, modular strategy for the first completely stereoselective synthesis of defined heparin oligosaccharides is described. Six monosaccharide building blocks (four differentially protected glucosamines, one glucuronic and one iduronic acid) were uti
Some key experimental features of a modular synthesis of heparin-like oligosaccharides
De Paz, Jose-Luis,Ojeda, Rafael,Reichardt, Niels,Martin-Lomas, Manuel
, p. 3308 - 3324 (2007/10/03)
The key features of a modular n+2 strategy for a completely stereoselective synthesis of oligosaccharides containing the GlcN-IdoA repeating unit of the major sequence of heparin are presented and discussed in detail. These key features include the regio-
AN EFFICIENT SYNTHESIS OF THE LEWIS A (Lea) ANTIGEN PENTASACCHARIDE MOIETY
Toepfer, Alexander,Schmidt, Richard R.
, p. 809 - 822 (2007/10/02)
Starting material for the synthesis of Lewis A pentasaccharide (1) was azidoglucose derivative 2 which was readily transformed into the 3,4-O-unprotected derivative 3 of the 3-O-unprotected derivative 5, respectively.Reaction of 3 and O-galactosyltrichlor
Stereoselective synthesis of glycobiosyl phosphatidylinositol, a part structure of the glycosylphosphatidylinositol (GPI) anchor of Trypanosoma brucei
Murakata, Chikara,Ogawa, Tomoya
, p. 75 - 92 (2007/10/02)
O-α-D-Mannopyranosyl-(1 -> 4)-O-2-amino-2-deoxy-α-D-glucopyranosyl-(1 -> 6)-1D-myo-inositol 1-(1,2-di-O-myristoyl-sn-glycer-3-yl hydrogen phosphate), a part structure of the glycosyl-phosphatidylinositol (GPI) anchor of Trypanosoma brucei, was synthesised