1: SnCl4 / acetonitrile / 18 h / Ambient temperature 2: 65 percent / POCl3, 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose / Molecular sieve 4A / CHCl3 / 24 h / 30 - 33 °C 3: 35 mg / Conc. HCl / ethanol / 4 h View Scheme

1: 65 percent / POCl3, 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose / Molecular sieve 4A / CHCl3 / 24 h / 30 - 33 °C 2: 35 mg / Conc. HCl / ethanol / 4 h View Scheme

1: 63.9 percent / m-Chloroperbenzoic acid / acetic acid 2: Ammonium sulfate / pyridine / 4 h / Heating 3: SnCl4 / acetonitrile / 18 h / Ambient temperature 4: 65 percent / POCl3, 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose / Molecular sieve 4A / CHCl3 / 24 h / 30 - 33 °C 5: 35 mg / Conc. HCl / ethanol / 4 h View Scheme

1: Ammonium sulfate / pyridine / 4 h / Heating 2: SnCl4 / acetonitrile / 18 h / Ambient temperature 3: 65 percent / POCl3, 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose / Molecular sieve 4A / CHCl3 / 24 h / 30 - 33 °C 4: 35 mg / Conc. HCl / ethanol / 4 h View Scheme

hydrogenchloride in ethanol 4 h;