Acetic Acid → HCID 10515470, Verbindung

Reaktionsgleichung

[C:1]([O:4][C@H:5]1[C@@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@H:10]([CH3:16])[O:9][CH:6]1OC)(=[O:3])[CH3:2].S(=O)(=O)(O)O.[C:22]([OH:25])(=[O:24])[CH3:23]>C(OC(=O)C)(=O)C>[C:22]([O:25][CH:6]1[O:9][C@@H:10]([CH3:16])[C@H:11]([O:12][C:13](=[O:15])[CH3:14])[C@@H:5]1[O:4][C:1](=[O:3])[CH3:2])(=[O:24])[CH3:23]

Komponenten

Versuchsvorschrift

Methyl 5-deoxy-2,3-di-O-acetyl-L-ribofuranoside (33 g, 15.2 mmol) was dissolved in acetic acid (20 mL) and acetic anhydride (5 mL). The solution was cooled to ice bath temperatures and concentrated sulfuric acid was added dropwise (1 mL). The solution was kept at 5° C. for 4 days, then it was poured into ice water (50 mL) and extracted with 3:1 ethyl acetate hexanes (200 mL and 75 mL). The combined organics were washed with 10% sodium biarbonate (2×50 mL) and water (50 mL). The organic layers were dried, and concentrated and the residue purified on a silica gel column (5×15 cm, 230-400 mesh) with ethyl acetate:hexanes (1:3). Both anomers were observed but were isolated together as a clear oil (2.2 g, 8.8 mmol, 58%); 1H NMR (DMSO-d6) δ5.96 (d, 1H J=1 Hz), 5.23 (d, 1H, H-2, J=5 Hz), 4.96 (t, 1H, H-3, J=5.7 Hz), 4.24-4.16 (m, 1H, H-4), 2.07 (s, 3H, OAc), 2.05 (s, 3H, OAc), 2.02 (s, 3H, OAc), 1.27 (d, 3H, H-5, J=6.3 Hz).