A New Access to Mori′s Intermediate for the Practical Synthesis of (-)- Periplanone-B.

Mori’s key intermediate 2 for the large-scale synthesis (−)-periplanone-B has been prepared from β-keto prenyl ester 8 by exploiting the new three-step sequence of α-alkynylation with alkynyllead(IV) triacetate, semihydrogenation, and palladium-catalyzed deallyloxycarbonylation with HCO2HNEt3, and subsequent isomerization induced by NaOCH3.