Improved total synthesis of the antibiotic A54145B

Org Biomol Chem. 2020 Apr 16. doi: 10.1039/d0ob00558d. Online ahead of print.

Abstract

A54145B is a calcium-dependent cyclic lipodepsipeptide antibiotic that is active against Gram-positive pathogens. Herein, we report an improved synthetic route toward A54145B in terms of the yield and time required. The key changes include using a pre-assembled minimalist tetradepsipeptide building block to solve the difficult on-resin esterification from our previous synthetic route, and a new macrocyclization site to avoid the peptide self-cleavage problem.