Studies Directed Toward the Total Synthesis of Nannocystin A

Abstract

A full account of our efforts directed toward the stereoselective total synthesis of nannocystin A, a macrocyclic myxobacterial metabolite, is presented. In this endeavor, we have attempted two distinct synthetic routes to access polyketide fragment (C1‐C11) of macrocyclic depsipeptide (21‐membered) natural product from readily accessible building blocks 1,3‐propanediol and benzaldehyde employing Evans aldol, CBS reduction, Heck cross‐coupling, and Sharpless asymmetric epoxidation as key transformations. Ultimately, accomplished the synthesis of the complete skeleton (21‐membered precursor for macrocyclic depsipeptide) of the nannocystin A possessing desired stereochemistry and functional groups.

Bi(III)-Catalyzed Synthesis of Substituted Furans from Hydroxy-oxetanyl Ketones: Application to Unified Total Synthesis of Shikonofurans J, D, E, and C

“…Continuing our interest in stereoselective total synthesis of bioactive natural products, and inspired by the fascinating activity profile of furylhydroquinone natural products, we embarked on the total synthesis of shikonofurans 1 – 4 . As described in Scheme , we envisioned a unified retrosynthetic analysis for shikonofurans J, D, E, and C. The oxidation followed by enantioselective prenylation, etherification, or esterification of 4-hydroxymethyl-2-aryl furan 5 would deliver the desired natural products 1 – 4 .…”