Sodium hydride → HCID 67301237, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 1α,3β-bis(tert-butyldimethylsilyloxy)-20(S)-hydroxypregna-5,7,16-triene (55.5 mg, 0.0993 mmol), sodium hydride (95%, 15 mg, 0.594 mmol) and 15-crown-5 (15 mg, 0.0681 mmol) in tetrahydrofuran (1 ml) was stirred at an external temperature of 72° C. for 1 hour, to which t-butyl bromoacetate (0.05 ml, 0.336 mmol) was then added at room temperature and further stirred at an external temperature of 72° C. for 5 hours and 15 minutes. After the reaction mixture was diluted with ethyl acetate, water was added dropwise under ice cooling. After washing with saturated aqueous sodium chloride, the organic layer was dried over anhydrous magnesium sulfate. After evaporation under reduced pressure to remove the solvent, the resulting residue was purified by preparative thin layer chromatography (0.5 mm×1 plate, hexane:ethyl acetate=10:1, developed once) to give the titled compound (55.1 mg, 82%) as a colorless oil.

Provenance & Evidence