72002-52-9Relevant articles and documents
Hydrogen-Bonding-Assisted Exogenous Nucleophilic Reagent Effect for β-Selective Glycosylation of Rare 3-Amino Sugars
Zeng, Jing,Wang, Ruobin,Zhang, Shuxin,Fang, Jing,Liu, Shanshan,Sun, Guangfei,Xu, Bingbing,Xiao, Ying,Fu, Dengxian,Zhang, Wenqi,Hu, Yixin,Wan, Qian
supporting information, p. 8509 - 8515 (2019/06/13)
Challenges for stereoselective glycosylation of deoxy sugars are notorious in carbohydrate chemistry. We herein report a novel strategy for the construction of the less investigated β-glycosidic bonds of 3,5-trans-3-amino-2,3,6-trideoxy sugars (3,5-trans-3-ADSs), which constitute the core structure of several biologically important antibiotics. Current protocol leverages a C-3 axial sulfonamide group in 3,5-trans-3-ADSs as a hydrogen-bond (H-bond) donor and repurposes substoichiometric phosphine oxide as an exogenous nucleophilic reagent (exNu) to establish an intramolecular H-bond between the former and the derived α-oxyphosphonium ion. This pivotal interaction stabilizes the α-face-covered intermediate to inhibit the formation of the more reactive β-intermediate, thereby yielding reversed β-selectivity, which is unconventional for an exNu-mediated glycosylation system. A wide range of substrates was accommodated, and good to excellent β-selectivities were ensured by this H-bonding-assisted exNu effect. The robustness of the current strategy was further attested by the architectural modification of natural products and drugs containing 3,5-trans-3-ADSs, as well as the synthesis of a trisaccharide unit in avidinorubicin.
Addition of Hydrazoique Acid to Pseudoglycals Stereoselective Synthesis of L-Acosamine and L-Daunosamine
Abbaci, Belgacem,Florent, Jean-Claude,Monneret, Claude
, p. 667 - 672 (2007/10/02)
Methyl and benzyl glycosides and glycal of L-acosamine (3-amino-2,3,6 trideoxy-L-arabino-hexose) have been stereoselectively prepared via 1,4-addition of hydrazoic acid to L-erythro-hex-2-enopyranose as a key step.Inversion of the C-4 configuration of met
CONVENIENT SYNTHESYS OF L-DAUNOSAMINE AND L-ACOSAMINE
Brimacombe, John S.,Hanna, Roderick,Tucker, Leslie C. N.
, p. 419 - 426 (2007/10/02)
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