Total synthesis of antiallergic bicyclic peptide seongsanamide A

The first total synthesis of antiallergic depsipeptide seongsanamide A has been achieved and also the relative and absolute stereochemistry of the natural product has been confirmed. Highlights of the convergent route include the use of Miyuara borylation, Chan-Evans-Lam coupling for the effective assembly of the isodityrosine subunit and the identification of an effective macrocyclization site in very high conversion. The longest linear sequence leading to seongsanamide A was 12 steps, with an overall yield of 12.7%.