the present invention is an oxidative process for the conversion of 21 - unsaturated progesterones ## str1 ## to the corresponding 3 , 5 - secoandrost - 5 - one - 3 , 17β - dioic acids ## str2 ## by use of either ozone or an oxidizing agent , which are useful intermediates in the production of δ 5 - 4 - aza - 17 - carbonyl steroids which are useful in production of 5α - 4 - aza amide pharmaceuticals . also disclosed are the novel 21 - unsaturated progesterones and 3 , 5 - secoandrost - 5 - one - 3 , 17β - dioic acids .