Synthetic studies toward the disorazoles: synthesis of a masked northern half of disorazole D1 and a cyclopropane analog of the masked northern half of disorazole A1

The synthesis of a masked northern half of the natural product disorazole D1 and a cyclopropane analog of the masked northern half of disorazole A1 is described. The synthesis involves in both cases as key steps a Z-selective Wittig olefination and a Sonogashira cross-coupling reaction.