Scalable total synthesis of a mycobactin T analogue utilizing a novel synthetic and protection strategy

Abstract

Mycobactin T analogue 1 (MbT-1) is a mycobacterial-specific siderophore analogue, which is usually employed to conjugate therapeutic drugs to induce selective antibacterial activity. In this article, the scalable total synthesis of MbT-1 was accomplished with a 16-step procedure in a total yield of 14%. A judicious choice of common intermediate 7 and reaction conditions allowed for the concise synthesis of two major building blocks B and D. Key steps included one-pot synthesis of chiral building block protected A, a novel protection strategy (O-Bz/t-BuCO₂/Cbz), and a selective deprotection method (O-Bz/Boc/Cbz), which could help in the syntheses of other mycobactin analogues.