Fluoxymesterone synthesis

Fluoxymesterone, 9-fluoro-11β,17β-dihydroxy-17α-methylandrost- 4-en-3-one (29.3.8), is made from 11β-hydroxy-4-androsten-3,17-dione, which is reacted with pyrrolidine to give a dieneamine (29.3.4). This undergoes a reaction with methylmagnesiumiodide, which after hydrolysis forms 11β,17β-dihydroxy-17α-methylandrost- 4-en-3-one (29.3.5). Dehydration of this compound by selective tosylation of the secondary hydroxyl group at C11 using p-toluenesulfonyl chloride and subsequent reaction with a base gives the diene (29.3.6), and the double bond at C9–C11 is transformed to an epoxide (29.3.7) by subsequent reaction with N-bromoacetamide in a wet solvent (source of HOBr), and a base. Further reaction with hydrogen fluoride results in an opening of the epoxide ring and the formation of the desired fluoxymesterone (29.3.8).