16-.alpha., 17-dihydroxy-6-.alpha.-methylpregn-4-ene-3,20-dione, cycli c acetal with acetone
16-.alpha., 17-dihydroxy-6-.alpha.-methylpregn-4-ene-3,20-dione, cycli c acetal with acetone(16-.alpha., 17-dihydroxy-6-.alpha.-methylpregn-4-ene-3,20-dione, cycli c acetal with acetone)