Short and Divergent Total Synthesis of (+)-Machaeriol B, (+)-Machaeriol D, (+)-Δ8 -THC, and Analogues.

Short and highly efficient stereoselective syntheses provide machaeriols and cannabinoids in a divergent approach starting from a common precursor, commercially available (S)-perillic acid. Key features of the novel strategy are a stereospecific palladium-catalyzed decarboxylative arylation and a one-pot sequence comprising a stereoselective hydroboration followed by oxidation or reduction of the corresponding intermediary boranes. The divergent approach is convincingly demonstrated by the five-step syntheses of (+)-machaeriol B, (+)-machaeriol D, and related analogues, and the four-step synthesis of (+)-Δ8 -THC and an analogue.
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