Acetonitrile → HCID 15476568, compound

Participants

Reaction Steps

To a suspension of 1-O-acetyl 2,3,5-tri-O-benzyl-4-thio-D-arabinofuranose (478 mg, 1 mmol) and cytosine (129.0 mg, 1 mmol) in anhydrosis acetonitrile (25 mmol) were added consecutively hexamethyldisilazane (HMDS, 162 mg, 1 mmol) and chlorotrimethylsilane (TMSCl, 434 mg, 4 mmol), and the mixture was stirred at room temperature for 0.5 hours. This solution was cooled to −78° C. Trimethylsilyltrifluoromethane sulfonate (267 mg, 1.2 mmol) was added and the resulting solution was stirred at −78° C. for another 2.5 h, after which time the reaction was essentially complete. The mixture was warmed to room temperature, concentrated to a small volume (5 mL), diluted with methylene chloride (50 mL) and then washed with water (20 mL) followed by saturated sodium bicarbonate and water. The organic layer was dried over MgSO4 and evaporated to dryness. The residue was purified by chromatography over silica gel (50 g. elution with CHCl3/MEOH 98:2) to afford 7 as 2:1α,β mixture (425.2 mg 80.0%) as a colorless syrup TLC (95:5 CHCl3/MEOH) Rf 0.65; MS z/e 553 (M+Li)+.

Provenance & Evidence