Aromatic Crown Ethers as Phase Transfer Catalysts in the Synthesis of N-Acetylglucosamine  -Aryl Glycosides

Abstract

The crown ether-catalyzed glycosylation of phenol, 4-methoxyphenol, and 4-nitrophenol was studied under phase transfer conditions in solid-liquid system. The asymmetric dibenzocrown esters are superior to [3.3]dibenzo-1 8-crown-6 and 15-crown-5 in the catalysis of these reactions. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 3; see also http://www.maik.ru.

Synthesis and investigation of antimicrobial activity of 8-hydroxyquinoline glucosaminides

“…Chemical shifts (CS) of the proton signals of the glyco side residues and aglycone parts of the compounds (V)-(VII) corresponded to the values obtained earlier [14][15][16] and literature data [13]. The influence of the neighboring pyridine nucleus on the CS value of the anomeric proton in 8 oxyquinoline glycosides (V)-(VII), which were shifted in the region of the weak field (δ 5.66, 5.72, and 5.73 ppm) in comparison with similar signals in the spectra of aryl glucosamidines [14][15][16] should be noted.…”

“…An effective approach suggested earlier for the aryl β D glucosaminide synthesis by glycosylation of aromatic hydroxyl containing compounds in the phase transfer (PT) catalytic system of solid potassium carbonate anhy drous acetonitrile was used to create O β glycoside link age in compounds (V)-(VII) (scheme) [14][15][16]. The interaction of equimolar amounts of chloride (I), hydroxyl derivatives (II)-(IV) and anhydrous potassium carbonate in the presence of the PT catalyst, 15C5, although it resulted in the target products (V)-(VII), pro vided low yields due to the formation of oxazoline (XI), as well as a series of unidentified products of carbohydrate destruction.…”

Copper-Catalyzed Anomeric O-Arylation of Carbohydrate Derivatives at Room Temperature

“…1-Phenyl-2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-D-glucopyranose. 28 1 H NMR (300 MHz, CDCl 3 ) δ 7.32−7.13 (m, 2H), 7.04− 6.79 (m, 3H), 5.61 (d, J = 8.7 Hz, 1H), 5.34 (dd, J = 10.5, 9.2 Hz, 1H), 5.20 (d, J = 8.2 Hz, 1H), 5.07 (app t, J = 9.5 Hz, 1H), 4.22 (dd, J = 12.2, 5.4 Hz, 1H), 4.16−3.99 (m, 2H), 3.90−3.70 (m, 1H), 2.00 (s, 3H), 1.99 (s, 3H), 1.97 (s, 3H), 1.88 (s, 3H). 13 1-Phenyl-2,3,6,2′,3′,4′,6′-hepta-O-acetylcellobiose 4i.…”