in tetrahydrofuran byproducts: CaCl2; (N2); using Schlenk techniques; dropwise addn. of soln. of Ph3SnCl in THF to cooled (-60°C) soln. of Ca(Sn(SnPh3)3)2 in THF; stirring for4 h; warming to room temp., removal of solvent in vac., addn. of Et2O/n-hexane (1:1); filtration; removal of solvent in vac., recrystn. from 1:1 mixt. of toluene and Et2O; elem. anal.;

1: tetrahydrofuran; ammonia 2: tetrahydrofuran View Scheme

in tetrahydrofuran byproducts: BaCl2, polystannane, Ph3SnSnPh3; (N2); using Schlenk techniques; dropwise addn. of soln. of Ph2SnCl2 in THF to cooled (-60°C) soln. of Ba(SnPh3)2 in THF; stirring for 4 h; gently warming to room temp., removal of solvent in vac., addn. of Et2O/n-hexane (1:1); filtration; removal of solvent in vac., crystn. from 1:1mixt. of toluene and Et2O for few days at -20°C; sepn. manually under microscope; elem. anal.;