Unique formation of oxapentacycloundecanones by catalytic flash vacuum thermolysis of tricyclo[5.2,1.0(2,6)]decenone epoxides using mineral solid acids
Derksen AJ, van der Waals ACLM, van Ham MHA, van Dongen M, Borkent JH, de Gelder R, Klunder AJH, Zwanenburg B
TETRAHEDRON LETTERS 41 (47): 9189-9193 NOV 18 2000

Abstract:
Tricyclodecenone exo- and endo-epoxides 1 and 9 underwent an unexpected isomerization to oxa-pentacycloundecanones 2 and 10, respectively, under flash vacuum thermolysis conditions using various solid acid catalysts. The structure of a derivative of 2 (R=CO2Et) has been elucidated by X-ray diffraction analysis. A tentative mechanism for the formation of 2 from 1 is proposed.