Total Synthesis of the Antimitotic Marine Macrolide (−)‐Leiodermatolide

Leiodermatolide is an antimitotic macrolide isolated from the marine sponge Leiodermatium sp. whose potentially novel tubulin‐targeting mechanism of action makes it an exciting lead for anticancer drug discovery. In pursuit of a sustainable supply, we report a highly stereocontrolled total synthesis (3.2 % yield) based on a convergent sequence of palladium‐mediated fragment assembly and macrolactonization. Boron‐mediated aldol reactions were used to configure the three key fragments 2 , 5 , and 6 by employing the appropriate enantiomer of the lactate‐derived ketone 7 .