18-Crown-6 → HCID 58866131, compound

Participants

Reaction Conditions

Reaction Steps

The above compound (5) (4.1 g) was dissolved in methylene chloride/pyridine (60–10 mL) and trifluoromethanesulfonic anhydride (2.89 mL) was adding under stirring at −20° C., and then the mixture was stirred at the same temperature for 30 minutes. To the reaction solution was added chloroform (50 mL) and, after washing with 1N hydrochloric acid and saline, the solution was dried over magnesium sulfate and the solvent was distilled off under reduced pressure. The resulting residue was purified by silica gel column chromatography (ethyl acetate:n-hexane 1:1) to obtain a compound, which was dissolved in acetonitrile (60 mL) and cesium acetate (1.77 g) and 18-Crown-6 (3.05 g) were added, followed by stirring at room temperature for 2 hours. To the reaction solution was added ethyl acetate (100 mL) and, after washing with saturated saline, the solution was dried over magnesium sulfate and the solvent was distilled off under reduced pressure. The resulting residue was purified by silica gel column chromatography (ethyl acetate:cyclohexane=1:4→1:3) to obtain the titled compound (791 mg) as a syrup.

Provenance & Evidence