Semisynthesis of an Antifungal Lipopeptide Echinocandin

This is the authors' abstract. We don't add key points for this paper.

Compound 1 is a macrocyclic lipopeptide belonging to the echinocandin family, which has been effective in treating systemic fungal infections. In this paper, we report a unique regio-, chemo-, and stereoselective synthesis of 1 in four steps from the deacylated nucleus 3 in an impressive 83% overall yield. Highlights of this synthesis include a selective reduction of the amide to the amine and a highly stereoselective (99:1 α/β) introduction of the 2-aminoethyl hemiaminal. In addition, the synthesis of the naphthoyl side chain was accomplished in three steps in 79% overall isolated yield from commercially available 6-bromo-2-naphthol.