5a,7a-Dimethyl-4,5,5a,5b,6,7,7a,9,10,10a,10b,11,12,12a-tetradecahydro-8H-cyclopenta[7,8]phenanthro[1,2-c][1,2,5]oxadiazol-8-one AIDS-160468 AIDS160468 NSC631057 NSC631058 {5-.Alpha.-Androstano[3,4-c]-1',2',5'-oxadiazol-17-one} {5-.Beta.-Androstano[3,4-c]-1',2',5'-oxadiazol-17-one}