81265-93-2

129666-75-7

18162-48-6

81256-88-4

129681-71-6

Synthesis of N-(9-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsilyl)oxy)-3-hydroxytetrahydrofuran-2-yl)-9H-purin-6-yl)benzamide from compound (CAS:129666-75-7) and tert-butyldimethylsilylene and the The general procedure for the compound (CAS:129681-71-6) was as follows: to a solution of tetrahydrofuran (THF, 800 mL) and pyridine (15 mL) of the product of the previous step (200 g, 296.9 mmol) was added sequentially silver cyanide (AgNCb, 83.2 g, 489.8 mmol, 1.65 equiv) and tert-butyldimethylchlorosilane ( TBSCl, 78.7 g, 522.5 mmol, 1.76 equiv). The reaction mixture was stirred at room temperature for 16 hours. After completion of the reaction, the reaction mixture was filtered, diluted with water (H2O, 1.0 L) and extracted with ethyl acetate (EtOAc, 3 x 1.0 L). The organic layers were combined, washed with brine (2 × 1.0 L), dried over anhydrous sodium sulfate (Na2SO4), and concentrated under reduced pressure. The residue was purified by silica gel (SiO2) column chromatography (eluent: petroleum ether/ethyl acetate=3/1 to 1/1) to afford the products D-2a (114 g, 145 mmol, 49% yield) and D-2b (53 g, 68 mmol, 23% yield).