Trimethylsilyl triflate → HCID 18336820, compound

Participants

Reaction Conditions

Reaction Steps

(2R,3R,4R)-4,5-bis(acetyloxy)-2-(5-ethylisoxazol-3-yl)tetrahydrofuran-3-yl acetate isomer 1 (193 mg) was dissolved in acetonitrile (5 ml) and treated sequentially with 2,6-dichloropurine (213 mg), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) (0.186 ml) and trimethylsilyl trifluoromethanesulphonate (TMSOTf) (0.225 ml) via a syringe over 5 min. The clear yellow solution was stirred at 22° C. for 40 h, at 60° C. for 21 h, and at 80° C. for 6 h. The mixture was cooled to room temperature and more DBU (0.186 ml) and TMSOTf (0.225 ml) were added. After stirring at 22° C. for 36 h the yellow mixture was heated at 60° C. overnight and at 80° C. for 6 h. The solvents were removed in vacuo and the resultant brown oily solid taken up in ethyl acetate and washed with water (20 ml, 3:1). The aqueous layer was extracted with ethyl acetate and the combined organic layers dried (MgSO4) and evaporated in vacuo to afford a brown oily solid. The residue was triturated with dichloromethane and a white solid removed by filtration. Evaporation of the filtrate afforded a tan solid. Purification by flash chromatography on silica gel eluting with ether:cyclohexane (1:1) afforded the title compound as a white solid (161 mg).

Provenance & Evidence