Patent ID: 7749988

Claim:
A method of treating a proliferative disease selected from cancer and leukemia, said method comprising administering a therapeutically effective amount of a compound of formula I, or a pharmaceutically acceptable salt thereof wherein: X 1 is C═O, C═NOR 1a , CHOR 1a , CHOCOR 1a , CHOCOY-Hal, CHOC(O)OR 9 , CHOC(O)OR 1a , CHOC(O)OR 10 , and Hal is Br, Cl, I, F; X 3 and R 8 together are CHOCOCH 2 and form a cyclic lactone; R 1-5 are each independently H or lower alkyl; R 6 is H or absent if “a” is a double bond; R 7 is H, COOR 1c , YOCOR 1c , COOYOCOR 1e , YCOOR 1e ; R 9 is an OH-substituted alkyl group, an ether group or a cyclic ether; R 10 is lower alkyl substituted Hal; “a” is a double bond or single bond; and wherein Y=(CH 2 ) n n=0 to 5; R 1a , R 1c and R 1e are each independently H or lower alkyl.