Sulfuric Acid → 2beta-Methoxy-3alpha-hydroxy-5alpha-pregnan-20-one

Participants

Reaction Steps

2α,3α-Epoxy-5α-pregnan-20-one (325 mg) in 80 mL of methanol was treated with a 1 mL solution of methanol containing 7 drops of concentrated sulfuric acid at room temperature. This mixture was stirred at this temperature for 10 minutes and then poured into a cold saturated solution of sodium bicarbonate and ether. The organic phase was washed several times with a small portion of bicarbonate, brine and dried over potassium carbonate. The concentrated organic phase was tested by TLC for complete reaction. Flash chromatography on silica gel with hexane/ethyl acetate solvent mixture (80:20) produced 209 mg (60% yield).

Provenance & Evidence