Formal total synthesis of palmerolide A.

A formal total synthesis of the 20-membered marine macrolide, palmerolide A from chiral pool tartaric acid is described. Elaboration of a γ-hydroxy amide, which is derived from the desymmetrization of tartaric acid amide, and Boord olefination are the pivotal reactions employed for the synthesis of the chiral building blocks, and Stille coupling and ring-closing metathesis (RCM) are used to assemble the macrolactone.