Intermolecular additions of cyclobutanone derived radicals. A convergent, highly efficient access to polycyclic cyclobutane containing structures

Abstract : a-Xanthyl cyclobutanones undergo intermolecular radical additions to olefins bearing various functional groups. Adducts containing a phosphonate can be made to cyclise by an internal Wittig-Horner-Emmons reaction to give cyclohexene and cycloheptene rings fused to the cyclobutane. © 2003 Elsevier Ltd. All rights reserved.