Total synthesis of RNA-polymerase inhibitor ripostatin B and 15-deoxyripostatin A.

Keep me skipped: a highly convergent total synthesis of ripostatin B, an inhibitor of the bacterial RNA polymerase, is described. The key steps to construct and avoid isomerization of the skipped triene are a double Stille cross-coupling reaction and a ring-closing metathesis. Furthermore, 15-deoxyripostatin A, a stable and conformationally locked analogue of ripostatin A, was prepared and tested in vivo.