54622-95-6Relevant academic research and scientific papers
Visible-Light-Mediated, Chemo- and Stereoselective Radical Process for the Synthesis of C-Glycoamino Acids
Ji, Peng,Zhang, Yueteng,Wei, Yongyi,Huang, He,Hu, Wenbo,Mariano, Patrick A.,Wang, Wei
supporting information, p. 3086 - 3092 (2019/05/01)
An approach for efficient synthesis of C-glycosyl amino acids is described. Different from typical photoredox-catalyzed reactions of imines, the new process follows a pathway in which α-imino esters serve as electrophiles in chemoselective addition reactions with nucleophilic glycosyl radicals. The process is highlighted by the mild nature of the reaction conditions, the highly stereoselectivity attending C-C bond formation, and its applicability to C-glycosylations using both armed and disarmed pentose and hexose derivatives.
Synthesis of l -Ribose from d -Ribose by a Stereoconversion through Sequential Lactonization as the Key Transformation
Ban, Jaeyoung,Shabbir, Saira,Lim, Minkyung,Lee, Byunghoon,Rhee, Hakjune
, p. 4299 - 4302 (2017/09/12)
l -Ribose, a key precursor of various l -nucleosides can only be synthesized from other sugars or other non-sugar precursors. Herein, the study involves the synthesis of naturally rare l -ribose from readily available d -ribose. Though, many synthetic strategies are developed to meet the increasing demands of l -ribose, seeking innovation, a synthesis employing sequential lactonization as the key transformation was explored. This novel conversion involves protection, oxidation, sequential lactonization, reduction with DIBAL-H, and deprotection..
A facile method for oxidation of primary alcohols to carboxylic acids and its application in glycosaminoglycan syntheses
Huang, Lijun,Teumelsan, Nardos,Huang, Xuefei
, p. 5246 - 5252 (2008/02/13)
A convenient two-step, one-pot procedure was developed for the conversion of primary alcohols to carboxylic acids. The alcohol was first treated with NaOCl and TEMPO under phase-transfer conditions, followed by NaClO2 oxidation in one pot. This reaction is applicable to a wide range of alcohols and the mild reaction conditions are compatible with many sensitive functional groups, including electron-rich aromatic rings, acid-labile isopropylidene ketal and glycosidic linkages, and oxidation-prone thioacetal, p-methoxybenzyl, and allyl moieties. Several glycosaminoglycans such as heparin, chondroitin, and hyaluronic acid oligosaccharides have been synthesized in high yields by using this new oxidation protocol.
Synthesis and biological activity of new potential agonists for the human adenosine A2A receptor
Bosch, M. Pilar,Campos, Francisco,Niubó, Itziar,Rosell, Gloria,Díaz, J. Luis,Brea,Loza, M. Isabel,Guerrero, Angel
, p. 4041 - 4053 (2007/10/03)
New adenosine derivatives have been synthesized and tested as putative agonists of adenosine receptors. Compounds 2-6 derive from the introduction of several types of substituents (electron donating, electron withdrawing, and halogens) in the para-position of the phenyl ring of the parent compound 1, and compound 7 lacks the hydroxyl group of amino alcohol 1. In radioligand binding assays using recombinant human A1, A2A, A2B, and A3 receptors, all compounds showed very low or negligible affinity for A1 and A2B receptors but compounds 3, 5, and 7 displayed a remarkably potent affinity for the A2A receptor with Ki values of 1-5 nM. Bromo derivative 3 displayed a selectivity A1/A2A = 62 and A3/A2A = 16 whereas the presence of a hydroxyl group (compound 5) improved the selectivity of A 1/A2A and A3/A2A to 120- and 28-fold, respectively. When the methoxy derivative 4 lacks the hydroxyl group on the side chain (compound 7), the binding affinity for A2A is increased to 1 nM, improving selectivity ratios to 356- and 100-fold against A1 and A3, respectively. In Chinese hamster ovary cells transfected with human A2A and A2B receptors, most compounds showed a remarkable activity for the A2A receptor, except chloro derivative 2, with EC50 values ranging from 1.4 to 8.8 nM. The compounds behaved as good A2A agonists, and all were more selective than 5′-(N-ethylcarboxamino)adenosine (NECA), with A2B/A 2A ratios of cAMP accumulation ranging from 48 for compound 2 to 666 for compound 7 while the corresponding A2B/A2A ratio for NECA was only 9. Compounds 1, 3, 5, and 7 also displayed higher selectivities than NECA up to 100-fold in isolated aortas of rat and guinea pig. In guinea pig tracheal rings precontracted by carbachol, compounds 2 and 4 were more potent than adenosine (100-fold) and NECA (10-fold), whereas compounds I and 7 displayed similar effects to NECA. Pretreatment of the tracheal rings with A2, A2A, and A2B receptor antagonists 3,7-dimethyl-L-propargylxanthine, 8-(3-chlorostyryl)caffeine, and alloxazine produced a marked inhibition of the tracheal relaxations induced by compounds 1, 2, and 4, but none of the compounds showed selectivity toward any of the adenosine receptors.
Oxidation of partially protected carbohydrates at the nickel hydroxide electrode
Schaefer, Hans J.,Schneider, Roy
, p. 715 - 724 (2007/10/02)
Primary hydroxy groups in pyranoses are oxidized in excellent yields to the corresponding carboxylic acids. In furanose 3 the yield of acid is only moderate. Secondary hydroxy groups are inert, aside from lactols. The different reactivity of secondary and primary hydroxy groups allows the chemoselective oxidation of 8 and 10.
