in tetrahydrofuran soln. AgCF3SO3 in THF was added dropwise to soln. 1,1'-(1-propene-1,3-diyl)-ferrocene in THF, react. mixt. was stirred for 1h; violatiles were removed in vacuo, residue was washed with Et2O and extd.into CH2Cl2, soln. was filtered and layered with pentane; elem. anal.;