Résumé/Abstract The total syntheses of the bicyclic sesquiterpene phenols (′)-α- herbertenol (1) and (′)-1, 4-cuparenediol (2) have been successfully accomplished involving copper-catalysed conjugate addition of Grignard reagents to unsaturated dinitriles and α, α-dimethylation of primary esters as key reactions. Oxidation of 2 afforded the sesquiterpene quinone 3.