Triquinanes from linear ketones via trimethylenemethane diyls

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.