in dichloromethane 1 mol of 2,2-bis(dimethylchlorostannyl)propane, CH2Cl2 and 0.5 mol of tetrachlorostannane placed into flask, warmed and solvent removed (vac.),warmed to 60°C overnight; stirred at 60°C under 0.01 Torr, recrystd. (petroleum ether); elem. anal.;

in dichloromethane CH2Cl2 added to 2,2-bis(dimethylchlorostannyl)propane, excess of SnCl4 added slowly, agitated for 5 min, concd. (vac.), heated at 60°C overnight; warmed to 60°C for 0.5 h with slow reducing pressure to 0.01 Torr, recrystd. (CCl4); elem. anal.;

in dichloromethane CH2Cl2 added to 2,2-bis(dimethylchlorostannyl)propane, excess of SnCl4 added slowly, agitated for 5 min, concd. (vac.), heated at 60°C overnight; warmed to 60°C for 0.5 h with slow reducing pressure to 0.01 Torr, recrystd. (CCl4); elem. anal.;

in neat (no solvent) 2,2-bis(trimethylstannyl)propane placed in flash with 2 mol of dimethyldichlorostannane, heated at 60°C overnight; stirred at 15-20 Torr, warmed at 0.01 Torr to 100°C, recrystd. (CCl4); elem. anal.;

in dichloromethane CH2Cl2 added to 2,2-bis(dimethylchlorostannyl)propane, excess of SnCl4 added slowly, agitated for 5 min, concd. (vac.), heated at 60°C overnight; warmed to 60°C for 0.5 h with slow reducing pressure to 0.01 Torr, recrystd. (CCl4); elem. anal.;