Stereoselective formal synthesis of aspergillide A

Abstract

The stereoselective formal synthesis of aspergillide A (1), a cytotoxic 14-membered macrolide, is disclosed. The key intermediate, a trisubstituted tetrahydropyran core is prepared by SmI 2 -induced intramolecular reductive cyclization as well as by using sequential α-aminooxylation, Horner-Wadsworth-Emmons olefination, and followed by Oxa-Michael cyclization. Other notable transformations in the synthesis include the use of Jacobsen's hydrolytic kinetic resolution, esterification, ring-closing metathesis (RCM), and cross-metathesis (CM) reactions.