Total synthesis of Epothilone E and related side-chain modified analogues via a stille coupling based strategy1This paper is dedicated with admiration and respect to the memory of Sir Derek H. R. Barton.1
A Stille couplingstrategy has been utilized to complete a totalsynthesis of epothilone E from vinyl iodide 7 and thiazole-stannane 8h. The central core fragment 7 and its trans-isomer 11 were prepared from triene 15 using ring-closing metathesis (RCM), and were subsequently coupled to a variety of alternative stannanes to provide a library of epothilone analogues 18a-o and 19a-o. The Stille coupling
Epothilone A, epothilone B, analogs of epothilone and libraries of epothilone analogs are synthesized. Epothilone A and B are known anticancers agents that derive their anticancer activity by the prevention of mitosis through the induction and stabilization of microtubulin assembly. The analogs of epothilone are novel. Several of the analogs are demonstrated to have a superior cytotoxic activity as compared to epothilone A or epothilone B as demonstrated by their enhanced ability to induce the polymerization and stabilization of microtubules.