Hydrochloric Acid → Methyl beta-D-ribofuranoside

D-ribose (2.0 g) was dissolved in methanol (40 ml), to which was added 1N methanolic HCl solution (4 ml) and the mixture was allowed to stand at 5° C to produce methyl β-D-ribofuranoside. The compound formed was dissolved in pyridine (50 ml) and the solution was subjected to action of nitrobenzoyl chloride 8.2 g at room temperature. The solvent was distilled off and the residue was dissolved in chloroform. The solution was washed with saturated sodium hydrogen carbonate solution, dried over anhydrous sodium sulfate and distilled to remove the solvent therefrom. Methyl 2,3,5-tri-O-(p-nitrobenzoyl)-β-D-ribofuranoside (4.2 g) thus obtained was dissolved in anhydrous dichloromethane (20 ml). To the solution was added acetic acid (20 ml) which had been saturated with hydrogen bromide under ice-cooling and the mixture was allowed to stand in the dark for 1 hour. The reaction solution was concentrated under a reduced pressure and the resulting sprupy concentrate was dissolved in dichloromethane. The solution was washed with a sodium hydrogen carbonate solution, dried over anhydrous sodium sulfate and distilled to remove the solvent therefrom. The residue was recrystallized from anhydrous benzene to obtain the titled compound. Yield 3.4 g.