Synonyms: Pregna-1,4-diene-3,20-dione,9,11b-dichloro-16a,17-dihydroxy-, cyclic acetalwith acetone (7CI,8CI); 2H-Naphth[2',1':4,5]indeno[1,2-d][1,3]dioxole,pregna-1,4-diene-3,20-dione deriv.; 9a,11b-Dichloro-16a,17a-isopropylidenedioxypregna-1,4-diene-3,20-dione