in tetrahydrofuran; hexane under N2 atm.; soln. of n-BuLi in hexane was added to soln. of complex in THF at -78°C in H-type Schlenk tube; mixt. stirred for 30 min at -78°C; several drops of BuLi in hexane were added; volatiles evapd. (vac.); pentane distd. onto mixt.; mixt. was stripped with pentane by distg. pentane onto the mixt. and evapg. in vac.; mixt. washed (pentane); volatiles removed (vac.);