Hydrochloric Acid → 17-Methyleneestra-4-EN-3-one

Participants

Reaction Steps

Con. hydrochloric acid (6.0 mL) and water (6.0 mL) were added to a solution of 17-methylenestra-2,5(10)-dien-3-yl methyl ether (15, 702.8 mg. 2.471 mmol) in methanol (6 mL) and acetone (20 mL). See Example 17. After stirring 1 h, sodium bicarbonate (7.50 g) was added cautiously. The mixture was concentrated under reduced pressure once effervescence had ceased and water (50 mL) was added. The mixture was extracted three times with 25 mL portions of methylene chloride. The combined organic extracts were washed with 50 mL of brine, dried over magnesium sulfate, and filtered through diatomaceous earth. The residue was washed with 10 mL of methylene chloride and the combined filtrates were concentrated under reduced pressure. The product was purified by decolorization with charcoal, flash chromatography (20% ethyl acetate/hexanes on silica gel), and recrystallization from aqueous ethanol to give a white powder (302.8 mg. 1.120 mmol, 45%), m.p. 83°-89° C. (NA-1994A-271)

Provenance & Evidence