The perhydrobenz[e]indene moiety of the stellettins and of the stelliferins, two families of isomalabaricane-type triterpenes with trans-syn-trans ring junctions, has been built from a bicyclic γ,δ-unsaturated aldehyde by a reaction sequence including a Lewis acid catalysed ene cyclisation to form a cyclopentanol, a hydroxyl-directed cyclopropanation, and the ring opening of a cyclopropyl ketone with trimethylsilyl iodide.