Synthesis of DEFG Ring of Complestatin and Chloropeptin I:  Highly Atropdiastereoselective Macrocyclization by Intramolecular Suzuki-Miyaura Reaction

Palladium-catalyzed intramolecular Suzuki-Miyaura reaction of linear tripeptide (23) afforded the 16-membered DEFG ring of complestatin (3) in good yield with an excellent atropdiastereoselectivity. Acidic treatment of 3 triggers a stereospecific rearrangement leading to the corresponding DEFG ring 4 of chloropeptin I.