| Abstrakt: |
Tri-O-acetyl-D-glucal (8) treated with a mixture of hydrogen peroxidemolybdenum trioxide undergoes a Ferrier rearrangement to form 2,3-unsaturated anomeric hydroperoxides 14 and 15.Tri-O-acetyl-D-galactal (10) and tri-O-benzyl-D-glucal (9), under the same conditions, afford the hydroperoxides in a low yield, whereas tri-O-benzyl-D-galactal (11) does not produce any unsaturated hydroperoxide. 2,3-Unsaturated anomeric hydroperoxides of α- and β-D-erythro- and α-D-threo-19, -20, and -24, respectively, were used for the enantioselective epoxidation of prochiral allylic alcohols 2527 and oxidation of sulfides 28 and 29 to give stereoselectivities of up to 50% enantiomeric excess. |
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