反应详情

To a solution of 4-[1-(2′,4′-dichloro-4-ethylbiphenyl-3-yl)-methylidene]-2,2,5,5-tetramethyldihydrofuran-3-one (2.04 g, 0.0051 mol) in methanol (24 ml) at 55° C. is added hydrogen peroxide solution (0.43 ml, 0.0076 mmol, 50% wt solution), followed immediately by aqueous lithium hydroxide (0.25 ml, 0.0005 mol). The reaction mixture is heated at this temperature for 30 minutes, then is rapidly cooled to room temperature and quenched with saturated sodium thiosulphate. The crude product is extracted with diethyl ether (×3), washed with saturated sodium bicarbonate, then dried over magnesium sulfate. The residue is purified by flash column chromatography (5% ethyl acetate in isohexane to 25% ethyl acetate in isohexane) to afford 2-(2′,4′-dichloro-4-ethylbiphenyl-3-yl)-4,4,6,6-tetramethyl-1,5-dioxaspiro[2.4]heptan-7-one as a yellow gum.

1. temperatureThe reaction mixture is heated at this temperature for 30 minutes
2. customquenched with saturated sodium thiosulphate
3. extractionThe crude product is extracted with diethyl ether (×3)
4. washwashed with saturated sodium bicarbonate
5. dry with materialdried over magnesium sulfate
6. customThe residue is purified by flash column chromatography (5% ethyl acetate in isohexane to 25% ethyl acetate in isohexane)