Hydrogen Peroxide → HCID 20726820, compound

Participants

Reaction Steps

n-Butyllithium (2.5 M in hexane, 40 ml, 100 mmol) was added to potassium tert-butoxide (1M in tetrahydrofuran, 100 ml, 100 mmol) at −70° C. under nitrogen atmosphere, followed by addition of diisopropylamine (19.1 g, 100 mmol) at the same temperature. After the mixture was stirred for 10 minutes, 17β-(t-butyldimethylsiloxy)-3-methoxyestra-1,3,5(10)-triene (10 g, 25 mmol) synthesized by the method described in Tetrahedron Lett., 3223 (1988) and dissolved in tetrahydrofuran (40 ml) was added dropwise at −70° C. over 10 to 15 minutes, and the resulting mixture was stirred for 4 hours. Trimethyl borate (15.6 g, 150 mmol) was added to the reaction mixture, which was then warmed to ice cold temperature and stirred for 1 hour and further stirred with 30% hydrogen peroxide (35 ml) for 1 hour at room temperature. The reaction mixture was cooled again on ice and 10% aqueous sodium thiosulfate (150 ml) was added to stop the reaction. After the reaction mixture was extracted with ether, the organic layer was washed with water and saturated aqueous sodium chloride, dried over anhydrous magnesium sulfate, and then filtered. After distilling off the solvent, the residue was purified by silica gel flash chromatography (eluent: hexane/ethyl acetate=5/1→3/1) to give 17β-(t-butyl-dimethylsiloxy)-3-methoxyestra-1,3,5(10)-trien-6-ol (8.38 g, Yield 82%).

Provenance & Evidence