Abstract: Compounds of the formula wherein R1 and R1′ are independently alkyl, aryl, alkenyl or alkynyl; R2 and R2′ are independently hydrogen, alkyl, aralkyl, alkoxyalkyl, hydroxyalkyl, haloalkyl, aminoalkyl, monoalkylaminoalkyl, dialkylaminoalkyl, acylaminoalkyl, alkylsulphonylaminoalkyl, arylsulphonyl-aminoalkyl, mercaptoalkyl, alkylthioalkyl, carboxyalkyl, alkoxycarbonylalkyl, aminocarbonylalkyl, alkylthio or alkylsulphinyl; R4, R5, R6, R7, R4′, R5′, R6′, and R7′ each independently are hydrogen, CO2R9, CH2OR10, CHO, CH2NR11R12, CON(R13)2, halogen, cyano, aryl, alkyl, hydroxy, alkoxy, aryloxy, haloalkyl, nitro, amino, aralkyloxy, acylamino, monoalkylamino, dialkylamino, thio, alkyl, alkylsulphinyl, alkylsulphonyl, arylsulphinyl, azide, phosphate or phosphonate provided that at least one of R4, R5, R6 and R7 and at least one of R4′, R5′, R6′, and R7′ are other than hydrogen, with the proviso that when R6 is methoxy, R5

Abstract: Compounds of the formula ##STR1## wherein R.sup.1, R.sup.1 ', R.sup.2, R.sup.2 ' R.sup.4, R.sup.5, R.sup.6 and R.sup.7 are as described herein;as well as pharmaceutically acceptable prodrugs or salts of acidic compounds of formula I with bases and or basic compounds of formula I with acids are antiproliferative agents useful in the treatment of cancer.

Abstract: Compounds of the formula ##STR1## wherein R is alkyl, alkylthio or hydroxy, as well as, pharmaceutically acceptable salts of compounds of formula I are antiproliferative agents useful in the treatment of cancer.

Abstract: Compounds of the formula ##STR1## wherein R.sup.1 and R.sup.1' are independently alkyl, aryl, alkenyl or alkynyl;R.sup.2 and R.sup.2' are independently hydrogen or alkyl;R.sup.4, R.sup.5, R.sup.6 and R.sup.7 each independently are ##STR2## CH.sub.2 OR.sup.10, CHO, CH.sub.2 NR.sup.11 R.sup.12, hydrogen, halogen, cyano, alkyl, hydroxy, alkoxy, aryloxy, haloalkyl, nitro, amino, acylamino, aralkyloxy, monoalkylamino, dialkylamino, alkylthio, alkylsulphinyl or alkylsulphonyl, provided that at least one of R.sup.4, R.sup.5, R.sup.6 or R.sup.7 is cyano, ##STR3## CH.sub.2 OR.sup.10, CH.sub.2 NR.sup.11 R.sup.12, or CHO ; R.sup.8 is alkyl, aralkyl or aryl;R.sup.10 is hydrogen, alkyl, aralkyl or aryl;R.sup.11 and R.sup.