Total synthesis of (-)-apicularen A.

A convergent total synthesis of (-)-apicularen A, a highly cytostatic 12-membered macrolide, has been accomplished. The key steps include assembling of iodoalkene 8 and aldehyde 9 by Nozaki-Hiyama-Kishi (NHK) coupling, stereospecific construction of 2,6-trans-disubstituted dihydropyran by Pd(II)-catalyzed 1,3-chirality transfer reaction, and Yamaguchi macrolactonization. Introduction of the (2Z,4Z)-heptadienamide moiety in the side chain by an efficient Cu(I)-mediated coupling completed the total synthesis.