Abstract
Rearrangement of Δ9(11)-17α-methyltestosterone derivatives to 18-norandrosta-8,11,13-trienes occurs readily in boiling methanoic acid. Activation of the 14α-hydrogen in the thermodynamic enol may facilitate the aromatisation of ring c in the case of Δ6,9(11)-17α-methyltestosterone. 17α-Ethynyloestradiol similarly gives a perhydrochrysene derivative, but cyanohydrins derived from 17-ketones are resistant to rearrangement under these conditions.