Abstract: A new photochemical reaction was utilized to functionalize unactivated carbon- hydrogen bonds in the C-I8 angular methyl group in steroids. The photolysis of 20- peracetoxy-20-cyanosteroids derived from 17-ketosteroids furnished I 8-cyano-20- ketosteroids, For example. the following sequence of reactions was applied to 3P- hydroxyandrost-5-en-I7-one (1 I):(I) protection of the hydroxyl group in 11 using ...