TOTAL SYNTHESIS OF (+)-GRINDELIC ACID BY STEREOCONTROLLED OXONIUM ION ACTIVATED PINACOL RING EXPANSION - CHEMICAL PROOF OF THE ABSOLUTE CONFIGURATION OF ALL GRINDELANE DITERPENES

摘要

(+)-Grindelic acid, synthesized enantioselectively from the levorotatory Wieland-Miescher ketone and (-)-linalool and necessarily formulated as 1a, is shown to be antipodal to the major diterpenoid of Grindelia species. [References: 34]