The present invention provides the compound having the structure: ##STR1## wherein each of R.sub.1 and R.sub.2 are independently the same as or different from each other; when R.sub.1 and R.sub.2 are the same, each is a substituted or unsubstituted arylamino, cycloalkylamino, pyridineamino, piperidino, 9-
purine-6-amine, or thiozoleamino group; when R.sub.1 and R.sub.2 are different, R.sub.1 =R.sub.3 --N--R.sub.4, wherein each of R.sub.3 and R.sub.4 are independently the same as or different from each other and are a
hydrogen atom, a hydroxyl group, a substituted or unsubstituted, branched or unbranched
alkyl, alkenyl, cycloalkyl,
aryl, alkyloxy, aryloxy, arylalkyloxy, or
pyridine group, or R.sub.3 and R.sub.4 bond together to form a
piperidine group and R.sub.2 is a hydroxylamino, hydroxyl, amino, alkylamino, dialkylamino or alkyloxy group; and n is an integer from about 4 to about 8. The present invention also provides a method of selectively inducing terminal differentiation of neoplastic cells and thereby inhibiting proliferation of such cells. Moreover, the present invention provides a method of treating a patient having a tumor characterized by proliferation of neoplastic cells. Lastly, the present invention provides a pharmaceutical composition and a therapeutically acceptable amount of the compound above.