research Highly efficient nucleophilic addition of alkyl Grignard reagents to 17-ketosteroids in the presence of cerium(III) chloride: Synthesis of 17α-propyl-17β-hydroxy-4-androsten-3-one, an androgen receptor antagonist
This study found that using anhydrous cerium(III) chloride with alkyl Grignard reagents significantly improved the addition to sterically hindered 17-ketosteroids, resulting in high yields and stereoselectivity.