Total Synthesis of Farnesin through an Excited‐State Nazarov Reaction
Yonglei Que, Hao Shao, Haibing He, Shuanhu Gao
Abstract
The asymmetric total synthesis of farnesin, a rearranged ent-kaurenoid, was achieved through a convergent approach involving photo-Nazarov and intramolecular aldol cyclizations to build the syn-syn-syn hydrofluorenol ABC ring system and bicyclo[3.2.1]octane CD ring system in the first application of a UV-light-induced excited-state Nazarov cyclization of a non-aromatic dicyclic divinyl ketone in a total synthesis. Unlike the conventional acid-promoted ground-state Nazarov reaction, the excited-state Nazarov reaction enables stereospecific formation of the highly strained syn-syn-syn-fused hydrofluorenone scaffold through a disrotatory cyclization.
Topics & Concepts
Excited stateTotal synthesisChemistryState (computer science)PhotochemistryComputer sciencePhysicsStereochemistryAtomic physicsAlgorithmBioactive Natural Diterpenoids ResearchAlkaloids: synthesis and pharmacologyPlant-based Medicinal Research