Water → Trifluoromethanesulfonate

Participants

Reaction Steps

To a solution of compound 1-1 (1.00 g) in methylene chloride (30 ml) were added under ice-cooling triethylamine (0.503 ml), anhydrous trifluoromethanesulfonic acid (0.607 ml), the mixture was stirred for 1 hr under ice-cooling. Water was added to the reaction mixture, and the mixture was extracted with methylene chloride, washed with water and saturated brine, and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane:ethyl acetate=1:2-1:4) to give acetonide deprotected compound with the protected phenolic hydroxyl group by a triflate (500 mg) as a colorless oil. Diisopropylamine (0.377 ml), heptanethiol (0.204 ml), 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos) (31 mg) and tris(dibenzylideneacetone)palladium(0)-chloroform adduct (27 mg) were added to a solution of the colorless oil in dioxane (10 ml), and the mixture was stirred at 120° C. for 4 hr. Water was added to the reaction mixture, and the mixture was extracted with ethyl acetate, washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane:ethyl acetate=1:2-1:3) to give the object product (390 mg) as a pale-yellow oil.

Provenance & Evidence