Trimethylsilyl triflate → (2R,3R,4R,5R)-2-(2-amino-6-chloro-9H-purin-9-yl)-5-((benzoyloxy)methyl)-3-methyltetrahydrofuran-3,4-diyl dibenzoate

Participants

Reaction Conditions

Reaction Steps

To a pre-cooled (0° C.) solution of (2S,3R,4R,5R)-5-(benzoyloxymethyl)-3-methyltetrahydrofuran-2,3,4-triyl tribenzoate (or 2,3,4,5-tetra-O-benzoyl-2-C-methyl-β-D-ribofuranose) (CarboSynth Ltd, 10.0 g, 17.22 mmol), 2-amino-6-chloropurine (Aldrich, 3.2 g, 18.87 mmol), and 1,8-diazabicycl[5.4.0]undec-7-ene (DBU) (7.7 mL, 51 mmol) in anhydrous acetonitrile (200 mL), was added trimethysilyl triflate (12.5 mL, 68.8 mmol) dropwise. The reaction mixture was then heated at 65° C. for 4 to 6 h, allowed to cool down to room temperature, poured into saturated aqueous sodium bicarbonate (300 mL), and extracted with dichloromethane (3×150 mL). The combined organic phase was dried over sodium sulfate and evaporated under reduced pressure. The residue was precipitated from dichloromethane and methanol, filtrated, the solid was washed 2 times with methanol and dried to give the desired compound (8.5 g, 79%) as a white solid (yields are from 65% (column) up to 90% (precipitation)).

Provenance & Evidence