Synthesis of biological evaluation of 4′-deshydroxy-4′-methyl etoposide and teniposide analogs

The E-ring 4′-deshydroxy-4′-methyl analogs of the clinical antitumor agents etoposide and teniposide were synthesized from the corresponding 4′-triflates. These compounds display significant antitumor activity against murine P388 leukemia in vivo but are only 1/5 as cytotoxic against a human colon tumor cell line (HCT-116) grown in culture. These analogs also show inferior activity vis-a-vis etoposide and teniposide when evaluated for their ability to inhibit purified human topoisomerase II.