Synonyms: Pregn-4-ene-3,20-dione,16a,17-dihydroxy-, cyclic acetalwith acetone (7CI,8CI); Progesterone, 16a,17-dihydroxy-, cyclic acetal with acetone (6CI); 16a,17-(Isopropylidenedioxy)progesterone;16a,17-Dihydroxypregn-4-ene-3,20-dionecyclic acetal with acetone; 16a,17a-Isopropylidenedioxyprogesterone;Algestone acetonide; Alphasone acetonide; NSC 26104; Progesterone16,17-acetonide; W 3395