Linear compounds containing a ketone and diene functional groups reacted with the anion of TMS-diazomethane to produce alkylidene carbenes that underwent intramolecular cyclopropanation followed by the formation of trimethylenemethane diyls which underwent [2+3] cycloaddition reaction to produce linearly fused triquinanes. (c) 2006 Elsevier Ltd. All rights reserved.