+: 1013.4155, found: 1013.4155.

4.1.6  9-[(2R,5R)-3-[2-({[(4R,6R)-6-(6-amino-9H-purin-9-yl)-2,2-dimethyl-tetrahydro-2H-furo[3,4-d] [1,3]dioxol-4-yl]methyl}amino)ethoxy]-4-[(tert-butyldimethylsilyl)oxy]-5-{[(tert-butyldimethylsilyl)oxy]methyl}oxolan-2-yl]-9H-purin-6-amine (20)
To a solution of 19 (210 mg, 0.20 mmol, 1.00 eq) in anhydrous DMF (10 mL) was added K2CO3 (85 mg, 0.61 mmol, 3.00 eq) and thiophenol (11 μL, 1.14 mmol, 5.70 eq). After stirring for 2 h at room temperature under argon, the reaction mixture was diluted with DCM (20