Total Synthesis of Icumazole A Using a Modified Cadiot–Chodkiewicz Coupling

The first total synthesis of myxobacteria metabolite icumazole A (1) is reported. Key steps in the route include an organocatalyzed asymmetric self-aldol reaction followed by an acetate aldol reaction to form the stereotriad present in the oxazole moiety, an intramolecular Diels–Alder reaction to form the isochromanone, and an acetylide addition and selective methylation. The final steps involved a high-yielding modified Cadiot–Chodkiewicz coupling and stereoselective reduction to secure the Z,Z-diene and afford 1.