Sulfuric Acid → 17-Hydroxypregna-4,9(11)-diene-3,20-dione

Participants

Reaction Steps

Mercuric oxide red (0.064 g) and concentrated sulfuric acid (0.086 ml) are stirred in water (1 ml) for 75 minutes at 67°. This mercuric oxide mixture is added to a mixture of 17β-ethynyl-17α-hydroxyandrosta-4,9(11)-dien-3-one (II A, Example 2, 0.84 g) in THF (5 ml) and methanol (24 ml) at 38°. This mixture is stirred for 3 hours and then cooled to 20°-25°. The mixture is quenched with phosphate buffer (pH=7, 10 ml) and then filtered to remove the insoluble mercury salts. The phases are separated and the aqueous layer is back-extracted with methylene chloride (3 times). The organic phases are combined and washed with saline, dried over sodium sulfate and concentrated under reduced pressure to give the title compound. NMR (CDCl3) 0.70, 1.42, 2.33, 5.60 and 5.80δ.

Provenance & Evidence