title: Total synthesis of (+)-lithospermic acid by asymmetric intramolecular alkylation via catalytic C-H bond activation.
abstract: The total synthesis of (+)-lithospermic acid is described. The efficient synthesis features an asymmetric alkylation via C-H bond activation to assemble the dihydrobenzofuran core of the natural product. This was accomplished via a chiral imine-directed C-H bond functionalization and represents the first application of this C-H activation method to natural product synthesis. Furthermore, a challenging deprotection of a late-stage permethylated lithospermic acid was achieved.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: O'Malley
authors.forename: Kian L
authors.initials: KL
authors.lastname: Tan
authors.forename: Anja
authors.initials: A
authors.lastname: Watzke
authors.forename: Robert G
authors.initials: RG
authors.lastname: Bergman
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Ellman
mesh_terms: D000478:Alkylation; D001572:Benzofurans / Q000138:chemical synthesis*; D002384:Catalysis; D053630:Depsides
chemical_list: D001572:Benzofurans; D053630:Depsides; C046833:lithospermic acid