Retinoyloxy aryl-substituted alkylene butyrates useful for the treatment of cancer and other proliferative diseases

A compound of Formula (I):

• ##STR9## wherein:
• Ret is selected from the group consisting of a retinoyl group, a therapeutically-active retinoid carbonyl group, a carbonyl group represented by the formula ##STR10## and retinoids which are C20 and C22 desmethyl vinylogs of said groups, wherein Z is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group or a cyclohexenyl group, and said phenyl or naphthyl group is substituted with from 0 to 5 substitutents selected from the group consisting of halo, hydroxy, alkyl, alkyoxy, amino, cyano, carboxy and carbalkoxy, and wherein double bonds in the polyene chain of any of said groups can have a cis or trans configuration;
• R is aryl or heteroaryl optionally substituted with halo, hydroxy, alkyl, alkoxy, amino, cyano, carbalkoxy, nitro, or trifluoromethyl;
• R.sub.1 is C.sub.1 to C.sub.7 alkyl, optionally substituted by a phenyl or substituted phenyl group;
• A is (CH.sub.2).sub.n or (CH.dbd.CH).sub.n ;
• n is 0 to 4;
• or a pharmaceutically acceptable salt thereof.