in tetrahydrofuran soln. of Sn-compound added to soln. of Ti-compound in hexane (-78°C), stirred, temp. raised to 0°C, soln. became dark-brown; solvent evapd. in vac., residue washed with pentane, dried; elem. anal., chromy.;

in tetrahydrofuran; hexane Sn-compound in THF added to Ti-compound (-78°C) in hexane, temp. raised to room temp., soln. became dark-brown; solvent evapd. in vac., residue dissolved in pentane, filtered, pentane evapd. under vac., distd.; elem. anal.;

in tetrahydrofuran addn. of Sn-compound in soln. to Ti-compound in hexane (-78°C), stirred, temp. raised to 0°C; solvent evapd. in vac., residue washed with pentane and dried; GLC;