Synonyms: Pregn-4-ene-3,20-dione,16a,17-dihydroxy-, cyclic acetalwith acetophenone (7CI,8CI); Progesterone, 16a,17-dihydroxy-, cyclic acetal with acetophenone (6CI);2H-Naphth[1',2':6,7]indeno[1,2-d][1,3]dioxole, pregn-4-ene-3,20-dione deriv.;16a,17-Dihydroxyprogesteroneacetophenide; 16a,17a-Dihydroxyprogesteroneacetophenide; NSC 67831; NSC 68280