Abstract

The synthesis of novel cyclic depsipeptide mimics by means of an organocatalytic conjugate addition, leading to chiral cyclic hemiacetals, followed by a multi component reaction with alpha-amino acids and isocyanides, is described. The initial organocatalytic step is employed for the asymmetric derivatization of alpha,beta-unsaturated aldehydes to 4,5-disubstituted 2-hydroxytetrahydropyrans, which are next used as chiral bifunctional substrates on the Ugi five-center three component reaction, giving rise to nine-membered-ring lactones. This sequential approach proved to be suitable for the rapid generation of molecular complexity through the combination of aliphatic, dipeptidic, glucosidic, and lipidic isocyanides with several amino acids, thus giving access to amido-, glyco-, and lipo-depsipeptide scaffolds featuring natural product-like structures.