Total synthesis of (+)-lithospermic acid by asymmetric intramolecular alkylation via catalytic C-H bond activation.
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.
O'Malley
Steven J
SJ
Department of Chemistry, University of California, Berkeley, California 94720, USA.
Tan
Kian L
KL
Watzke
Anja
A
Bergman
Robert G
RG
Ellman
Jonathan A
JA
D000478:Alkylation; D001572:Benzofurans / Q000138:chemical synthesis*; D002384:Catalysis; D053630:Depsides
D001572:Benzofurans; D053630:Depsides; C046833:lithospermic acid