Hydrogen Peroxide → 1alpha,3beta-bis(tert-butyldimethylsilyloxy)-20(S)-(3-hydroxy-3-methylbutyloxy)pregna-5,7,16-triene

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Reaction Steps

After a mixed solution of 1α,3β-bis(tert-butyldimethylsilyloxy)-20(S)-hydroxypregna-5,7,16-triene (97 mg, 0.175mmol), sodium hydride (50 mg, 2.08 mmol) and 4-bromo-2,3-epoxy-2-methylbutane (145 mg, 0.877 mmol) in tetrahydrofuran (2 ml) was heated under reflux for 12 hours, 1M lithium tri-s-butylborohydride solution in tetrahydrofuran (1.8 ml, 1.80 mmol) was added and the mixed solution was heated under reflux for 45 minutes. The reaction solution was stirred with 3N aqueous sodium hydroxide solution and 30% aqueous hydrogen peroxide at room temperature for 30 minutes, then diluted with ethyl acetate, washed with brine and dried over magnesium sulfate. The solvent was distilled off under reduced pressure and the resulting residue was purified by column chromatography (hexane:ethyl acetate=10:1) to give the title compound as a colorless oil (113 mg, 100%).

Provenance & Evidence