A new synthesis of a 2,3-epimino-α-D-allopyranoside

The Synthesis and Glycoside Formation of Polyfluorinated Carbohydrates

“…465 Its a-methyl glycoside 1021 was then obtained, and the 4,6-positions protected as benzylidene acetal 1022. 466 Protection of OH-3 as benzyl ether 1023 was followed by benzylidene acetal hydrolysis to allow activation to the 4,6-di-O-mesylate 1025. 467 Fluoride substitution to give 1026 could be achieved with TBAF in refluxing acetonitrile or with KF in refluxing ethylene glycol, the latter having a much shorter reaction time.…”

Precise structure activity relationships in asymmetric catalysis using carbohydrate scaffolds to allow ready fine tuning: dialkylzinc–aldehyde additions

“…On completion the reaction was filtered, concentrated under reduced pressure and purified by column chromatography. 34 1.1 Equivalents of ethyl iodide (63 µL) and potassium carbonate (108 mg) were used; the reaction was heated at 60 ЊC for a total of 22 h, a further 0.5 equivalents of ethyl iodide (29 µL) were added after 10 h. Purification by column chromatography (5-20% MeOH-EtOAc) afforded 4b (123 mg, 56%) as a white solid; R f 0.1 (10% MeOH-EtOAc); mp 97-99 ЊC (DCM-cyclohexane) {lit. 34…”

“…D ϩ91 (c 1.30, CHCl 3 ) {lit 34. [α] 24 D ϩ107 (c 1, CHCl 3 )}; ν max / cm Ϫ1 (KBr) 3428br, 3296 (OH, NH), 2928, 2865 (CH, aliphatic), 1624w (NH, δ), 1454 (CC, aromatic); δ H (400 MHz, CDCl 3 ) 7.51-7.49 (2H, m, Ph), 7.38-7.34 (3H, m, Ph), 5.57 (1H, s, CHPh), 4.91 (1H, d, J 3.5, H-1), 4.26 (1H, dd, J 9.6 and 4.0, H-6), 4.09 (1H, pt, J 9.6, H-3), 3.80 (1H, ddd, J 10.3, 9.0 and 4.0, H-5), 3.74 (1H, pt, J 9.9, H-6Ј), 3.64 (1H, pt, J 9.2, H-4), 3.44 (3H, s, OCH 3 ), 3.06 (1H, dd, J 9.9 and 3.5, H-2), 2.98 (1H, dq,…”

Ring-Opening Reactions of the N-4-Nosyl Hough–Richardson Aziridine with Nitrogen Nucleophiles

“…One of the frequently used methods leading to the derivatives of 2,3-diaminohexapyranosides is the ring-opening reaction of the Hough–Richardson aziridine, which is commonly synthesized from d -glucosamine. This valuable chiral intermediate can be transformed by regioselective ring-opening reaction of the strain-loaded three-membered ring into the corresponding diastereoisomers with α- d -altro or α- d -gluco configurations.…”