Terpenes and terpene derivatives, XXXIV. Synthesis of rac‐porosadienone

Abstract (±)‐Porosadienone (9) is easily synthesized by starting from (±)‐2,6‐dimethylcyclohexanone via indenone 1 and dienone 4. All compounds (rac‐4‐6 and rac‐9) with the α,β,γ,δ‐dienone system are very prone to air oxidation forming the corresponding mono epoxides rac‐7, rac‐8, rac‐10, and rac‐11.