Annulation strategy for the biomimetic synthesis of cis-fused diterpenoids

Concise and efficient formal syntheses of the A/B cis-fused ring C-aromatic tricyclic diterpenes, xanthoperol, and cis-A/B-coleon V are reported, via the application of domino reactions followed by a novel annulation method, in which the highly substituted target molecules are assembled from an acyclic precursor, namely the easily accessible monoterpene, citral.