1,4-Dioxane → L-Ribose

温度

40 °C

1-O-benzoyl-2,3-O-isopropylidene-L-ribonofuranoate (10 g) prepared in Example 6 was dissolved in a solvent mixture of methanol (30 ml) and 1.0N aqueous sodium-hydroxide solution (10 ml) and then reacted for about 3 hours. After TLC revealed the completion of reaction, the reaction solution was distilled under reduced pressure, water (10 ml) was added, and the reaction mixture was extracted two to three times with ethyl acetate. The extract was dried over magnesium sulfate and distilled under reduced pressure to give 2,3-isopropylidene-L-ribose (6.0 g). The compound thus obtained was dissolved in a solvent mixture of dioxane (12 ml) and water (12 ml), 1.0N hydrochloric acid solution (200 μl) was added, and then reaction was carried out for about 24 hours while maintaining the temperature of the reaction vessel of 40° C. After TLC revealed the completion of reaction, the solvent was removed by distillation under reduced pressure. The residue was dissolved in water (30 ml) and washed with ethyl acetate. Water was removed by distillation under reduced pressure to give a compound in the form of an oil. The compound thus obtained was purified by silica gel column chromatography (eluent: chloroform/methanol=4/1, v/v) to give the title compound (4.1 g, Yield 80%).