Transannular Cyclization of Epoxycaryophyllenes Catalyzed by Ti^III: An Efficient Synthesis of Tricyclo[6.3.0.0^2,5]undecanes

Abstract

Abstract The transannular cyclization of epoxycaryophyllenes 2 – 7 catalyzed by Ti III has been investigated. This cyclization led to alcohols 8 – 15 , all of them possessing a tricyclo[6.3.0.0 2,5 ]undecane skeleton. All of these compounds present pleasant aromatic properties. The cyclization takes place with high yields (> 80 %) and via the αα or ββ conformation of the intermediate radical I . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)