Hydrochloric Acid → 2,3:5,6-DI-O-Cyclohexylidene-alpha-D-mannofuranose

Participants

Reaction Conditions

Reaction Steps

To a mixed solution of 150 ml of cyclohexanone and 120 ml of dichloromethane were added 10.0 g of D-mannose, 200 mg of cupric acetate monohydrate and 1 ml of a 2 mole/l solution of hydrogen chloride in dioxane, and the mixture was stirred for 7 hours under reflux in a warm-water bath at 65° C. The refluxing solvent was continuously dried with 20 g of molecular sieves 3A which was placed between the reaction vessel and the cooling tube. After the conclusion of the reaction, the reaction solution was diluted with benzene, washed with aqueous sodium hydrogen-carbonate and water, and dried over anhydrous magnesium sulfate. When the solvent and cyclohexanone were distilled off under reduced pressure, there was obtained 17.5 g (92.6%) of 2,3:5,6-di-O-cyclohexylidene-α-D-mannofuranose as a residue. The compound, when recrystallized from hexane, showed a melting point of 122° to 124° C.

Provenance & Evidence