General procedure for the synthesis of 4-amino-1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-2(1H)-pyrimidinone: 4-amino-1-(3,5-di-O-benzoyl-2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-2(1H)-pyrimidinone (3.60 mmol) was dissolved in saturated ammonia methanol solution (30 mL ) in saturated ammonia methanol solution (30 mL) and the reaction was stirred at room temperature for 15 hours. After completion of the reaction, the solvent was removed by concentration under reduced pressure to obtain the crude product. 5.64 (dd, J = 19.44 Hz, 1H, H-3'), 5.26 (d, J = 48.2 Hz, 1H, H-2'), 4.50 (m, 1H, H-4'), 3.70-3.77 (m, 2H, H-5').
