Syntheses with anhydro sugars. XI. Preparation of 2-deoxy-2-fluoro-D-glucose and 2,4-dideoxy-2,4-difluoro-D-glucose

A Study of Intramolecular Hydrogen Bonding in Levoglucosan Derivatives

“…Levoglucosan derivatives 5 [ 16 ], 7 , and 8 [ 17 ] were obtained by hydrogenolysis using Pearlman’s catalyst of the known 10 [ 18 ], 12 [ 18 ], and 13 [ 17 , 18 ] in excellent yields while 6 [ 19 ] was obtained in a two steps sequence methylation-hydrogenolysis of the known 11 [ 20 ] ( Scheme 1 ). The known compounds 4 [ 12 , 21 ] and 9 [ 21 , 22 ] were obtained as described.…”

The synthesis of mono- and difluorinated 2,3-dideoxy-d-glucopyranoses

“…13,14,15 From 6, the synthesis of 4 started by a regioselective epoxide opening with potassium hydrogen bifluoride in refluxing ethylene glycol, 16,17 in a reasonable 65% yield (74% on small scale). Jensen recently reported a 40% yield under these conditions, which they could improve to 69% when conducted in a sealed vessel under microwave conditions at 220 °C.…”

Synthesis of Fluorine‐Containing Molecular Entities Through Fluoride Ring Opening of Oxiranes and Aziridines

“…The use of microwave heating instead of conventional heating enables the reaching of higher temperatures, which often accelerates reactions or improves their yield. Viuff et al found that compared to the original report by Pacák et al, ring opening of sugar‐derived epoxide 80 with KHF 2 provides higher yield and better selectivity when microwave heating is applied (Scheme ) . The reason apart from the selectivity of this reaction is that the substrate is a bridged, rigidified epoxycyclohexane, which prefers to open directly into a chair conformer (see Scheme and related discussion about the Fürst–Plattner rule).…”