55 g of 3,3-ethylenedioxy-17β-hydroxy-1α-methyl-5α-androstane in 550 ml of toluene and 110 ml of cyclohexanone were treated at boiling with a solution of 5.5 g of aluminium isopropylate in 55 ml of toluene and the mixture was heated for 3 hours with slow distillation. The mixture was then treated with ether, washed with ice-cold dilute sulphuric acid and water, evaporated and the residue steam-distilled. After extraction with methylene chloride, the resulting product was recrystallised from diisopropyl ether to give 51 g of 3,3-ethylenedioxy-1α-methyl-5α-androstan-17-one of melting point 155.5°-156.6° C.
