The general procedure for the synthesis of 1-((2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)tetrahydrofuran-2-yl)pyrimidin-2(1H)-one from the compound (CAS: 52523-24-7) was as follows: compound 15 (9.5 g, 17.6 mmol) was dissolved in methanol (100 mL) and cooled to 0 °C. To this cooled solution a methanol solution of 7N ammonia (245 mL) was slowly added. The reaction mixture was stirred at 25°C for 24 hours. Upon completion of the reaction, the solvent was removed by evaporation under reduced pressure. The residue was diluted with water and extracted with chloroform. The organic layer was dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (dichloromethane: methanol = 10:1) to afford compound 16 (3.8 g, 94% yield) as a white solid. Its 1H NMR (400 MHz, methanol-d4) data were as follows: δ 8.79 (dd, J = 6.8, 2.8 Hz, 1H), 8.57 (dd, J = 4.0, 2.8 Hz, 1H), 6.58 (dd, J = 6.8, 4.4 Hz, 1H), 5.86 (s, 1H), 4.15-4.10 (m, 3H), 3.98 ( dd, J = 12.4, 2.0 Hz, 1H), 3.79 (dd, J = 12.8, 2.0 Hz, 1H).
