Biomimetic\nSynthesis of Azorellolide via Cyclopropylcarbinyl\nCation Chemistry

A concise\nsynthesis\nof the complex diterpene azorellolide, inspired\nby speculations on biosynthetic cationic cascades, is presented. The\napproach, guided by computation, relies on the intramolecular interception\nof a cyclopropylcarbinyl cation by an appended carboxylate. The successful\nexecution of this strategy was achieved through acid-catalyzed isomerization\nof a β-lactone in competition with a type I dyotropic rearrangement.