Enantioselective Total Synthesis of (-)-Δ 9 -Tetrahydrocannabinol via N-Heterocyclic Carbene Catalysis

Adam Ametovski, David W. Lupton

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26 Citations (Scopus)


Enantioselective syntheses of (-)-Δ 8 -tetrahydrocannabinol ((-)-Δ 8 -THC) and (-)-Δ 9 -THC have been achieved in eight and 10 steps, respectively, from a known cinnamic acid. The syntheses take advantage of an enantioselective N-heterocyclic carbene (NHC)-catalyzed (4 + 2) annulation between donor-acceptor cyclobutanes and cinnamoyl fluorides to construct the highly enantioenriched cycloxyl β-lactone shown. Having constructed this A-ring precursor, elaboration to (-)-Δ 8 -THC is achieved through β-lactone alcoholysis followed by oxidation, dual decarboxylation, trimethylation, and cationic cyclization. Finally, the conversion to (-)-Δ 9 -THC is achieved with established chemistry.

Original languageEnglish
Pages (from-to)1212-1215
Number of pages4
JournalOrganic Letters
Issue number4
Publication statusPublished - 1 Jan 2019

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