3-(2,3,5-Tri-O-benzoyl-beta-D-Ribofuranosyl)thiazolo[4,5-d] pyrimidine-2,7(6H)-dione → 3-((2R,3R,4S,5R)-3,4-Dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl)thiazolo[4,5-d]pyrimidine-2,7(3H,4H)-dione

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Reaction Steps

Compound 9 (1.0 g, 1.63 mmol) was combined with methanolic ammonia (saturated at 0° C., 50 mL) and heated at 90° C. for 14 h in a steel bomb. The solvent was evaporated and the residue was treated with hot benzene which was decanted off. The resulting solid was purified by silica gel flash chromatography using chloroform and then CHCl3 -MeOH (6:1) to yield 280 mg (57%) of 10 after crystallization from water: mp 216°-218° C.: UV λmax (pH 1) 217 nm (ε 25,300), 259 (9700), 286 (6300): 1H NMR (DMSO-d6) δ 5.85 (d, J=5.1 Hz, 1H, C1, H), 8.30 (s, 1H, C5H), 13.09 (b, 1H, N6H, exchanges with D2O), and other sugar protons. Anal. Calcd. for C10H11N3O6S: C, 39.87: H, 3.68: N, 13.95: S, 10.64. 3.61: N, 14.06: S, 10.43.

Provenance & Evidence