6.01 g of 17β-hydroxy-1-methylandrosta-1,4-dien-3-one is dissolved in 100
ml of acetone. At room temperature, 22 ml of a chromic acid solution
(prepared from 6.67 g of CrO3, 6 ml of concentrated sulfuric acid, replenished
with water to 100 ml) is added dropwise to this solution. The mixture is
stirred for one hour and then precipitated into ice water, the product is
suctioned off and dried, thus obtaining after recrystallization from
acetone/hexane 5.25 g of 1-methylandrosta-1,4-diene-3,17-dione, melting
point 165-166°C.
