Abstract
Described herein is a catalytic asymmetric total synthesis of (−)-actinophyllic acid, with the key step being a chiral phosphine-catalyzed [3 + 2] annulation between an imine and an allenoate to form a pyrroline intermediate in 99% yield and 94% ee. The synthesis also features CuI-catalyzed coupling between a ketoester and a 2-iodoindole to shape the tetrahydroazocine ring; intramolecular alkylative lactonization; SmI2-mediated intramolecular pinacol coupling between ketone and lactone subunits to assemble the complex skeleton of (−)-actinophyllic acid; and an unprecedented regioselective dehydroxylation.
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/jacs.6b00567.
