n-butyllithium in ethylene glycol dimethyl ether soln of LiCp and EtOtf stirred under N2 at 0°C, then for 1 h at room temp. and recooled to 0°C, treated with n-BuLi in hexane, after 2 h ZrCl4 in glyme was added, stirred overnight; filtered, evapd. to dryness under vac., recrystd. from hot hexane; elem. anal.;

in tetrahydrofuran addn. of ZrCl4 at 0°C to freshly prepared C5H4C2H5Li in THF withstirring over 0.5 h, mixture stirred for further 24 h at 20°C; THF removed under vac., residue extd. with boiling toluene and little activated charcoal, filtered, addn. of hexane to filtrate, cooling to -30°C, elem. anal.;