Enantioselective Total Synthesis of Blennolide H and Phomopsis-H76 A and Determination of Their Structure

Chemistry. 2018 Jun 21;24(35):8760-8763. doi: 10.1002/chem.201801323. Epub 2018 May 25.

Abstract

This work reports on the enantioselective total synthesis of the two dimeric natural chromanone lactones phomopsis-H76 A (5) and blennolide H (6). Both syntheses could be achieved from chromane 11, which was obtained by an enantioselective Wacker-type cyclization with >99 % ee. The dimerization of the corresponding monomers was performed using a palladium-catalyzed Suzuki reaction. Moreover, within this work it was possible to revise the absolute configuration of phomopsis-H76 A and determine the relative as well as absolute configuration of blennolide H.

Keywords: Suzuki reaction; Wacker oxidation; chromanones; natural products; total synthesis.