Hydrochloric Acid → HCID 70166578, compound

Participants

Reaction Conditions

Reaction Steps

—Hydrogen chloride gas was passed into a solution of (3β,20S)-21-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-4,4,20-trimethylpregna-5,7-dien-3-ol benzoate (compound 8; Example 1, step vi; 25.0 g) and acetic anhydride (40 ml) in chloroform (250 ml) for 30 min. The mixture was heated at reflux temperature for 50 min.; addition of hydrogen chloride gas was continued for the first 20 min. After cooling to 0° C., an aqueous solution of ammonium hydroxide (5%) was added, and the mixture was stirred for 1.5 h. The product was extracted into dichloromethane; the combined organic phases were washed with a saturated aqueous solution of sodium hydrogencarbonate and brine, dried over sodium sulfate and concentrated under reduced pressure to give (3β,5α,20S)-21-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-4,4,20-trimethylpregna-6,8(14)-dien-3-ol benzoate (24.6 g). The product was used as such in the next step.

Provenance & Evidence