Synthesis of the sesquiterpene (±)-ceratopicanol: Use of radicals derived from epoxides

The sesquiterpene (±)-ceratopicanol [(±)-1] was synthesized by a route based on Claisen rearrangement (7 → 8) and radical cyclization (16α, 16β → 17α, 17β). Certain limitations on vinyl radical cyclization were observed, and so the required radical was generated by titanium-induced opening of an epoxide.