Convergent stereospecific synthesis of LL-Z1640-2 (or C292), hypothemycin and related macrolides. Part 2

The total synthesis of C292 (or LL-Z1640-2) and hypothemycin has been achieved. The 14-membered ring formation was achieved either via an intramolecular Suzuki coupling or much more efficiently via a Mitsunobu macrolactonisation. Reaction conditions were found to preserve the Z enone; selective epoxidation of C292 afforded hypothemycin.