HCID 20593839, compound → HCID 12135235, compound

Participants

Reaction Steps

Methyltriphenylphosphonium bromide (2.2 g, 6 mmol) was added to a stirred solution of potassium t-butoxide (680 mg, 6 mmol) in 25 ml dry THF under a nitrogen atmosphere. The yellow suspension was stirred for 30 minutes at room temperature. A solution of (7α)-7-methyl-3-keto-17-methyleneestr-5(10)ene (850 mg, 3 mmol) in 25 ml dry THF was added rapidly (approx. 30 seconds) to the suspension, resulting in a slightly exothermic reaction. The reaction mixture was stirred for 30 minutes at room temperature, poured on ice-water (100 ml) and extracted with ethyl acetate (100 ml). The organic layer was washed with water (50 ml), dried (Na2SO4) and evaporated to dryness to give (7α)-7-methyl-3,17-dimethyleneestr-5(10)ene (680 mg, 80%) as a colorless oil. [α]D +115° (c 0.185 in ethanol).

Provenance & Evidence