1: 3,5-di-O-benzyl-1,2-O-isopropylidene-4-C-methanesulfonyloxymethyl-α-D-ribofuranose With water; acetic acid T=90°C; Hydrolysis; 3 h; 2: acetic anhydride With pyridine T=20°C; Acetylation; 12 h;

1.1: dibutyltin oxide / methanol / 1 h / Heating 1.2: 19 percent / Bu4NBr / toluene / 15 h / Heating 2.1: 92 percent / pyridine 3.1: AcOH; H2O / 3 h / 90 °C 3.2: 54 percent / pyridine / 12 h / 20 °C View Scheme

1.1: dibutyltin oxide / methanol / 1 h / Heating 1.2: 19 percent / Bu4NBr / toluene / 15 h / Heating 2.1: 92 percent / pyridine 3.1: AcOH; H2O / 3 h / 90 °C 3.2: 54 percent / pyridine / 12 h / 20 °C View Scheme

1.1: 92 percent / pyridine 2.1: AcOH; H2O / 3 h / 90 °C 2.2: 54 percent / pyridine / 12 h / 20 °C View Scheme