in dichloromethane N2 atmosphere, addn. of soln. of stannyl compound to soln. of borane at -78°C (3 h) with stirring, slow warming to room temp., stirring (room temp., 17 h); removement of solvent (25°C, 13 Torr) and Me3SnBr (30°C, 1E-2 Torr or 53-55°C, 12 Torr), distillation (63-66°C, 1E-5Torr), cryst.; elem. anal.;

in dichloromethane (argon); stirring (2 h); solvent removal (vac.), extn. (hexane), evapn. (vac.), trituration with CH2Cl2/benzene;

in dichloromethane N2 atmosphere, addn. of soln. of stannyl compound to soln. of borane at -78 to -70°C (80 min), slow warming to room temp., stirring (roomtemp., 20 h); removement of solvent (25°C, 13 Torr) and Me3SnBr (34°C, 1E-3 Torr), distillation (82-86°C, 1E-3 Torr and 40-41°C, 1E-5 Torr); elem. anal.;

in dichloromethane N2 atmosphere, addn. of soln. of stannyl compound to soln. of borane at -70 to -40°C (80 min), slow warming to room temp., stirring (roomtemp., 16 h); NMR-monitoring, not isolated;

in dichloromethane N2 atmosphere, addn. of soln. of stannyl compound to soln. of borane at -70 to -60°C (1 h) with stirring, slow warming to room temp., stirring (room temp., 20 h); removement of solvent (25°C, 13 Torr), sublimation of Me3SnCl (25°C, 1E-3 Torr), cryst. (CH2Cl2); elem. anal.;

in dichloromethane N2 atmosphere, addn. of soln. of stannyl compound to soln. of borane at -70 to -60°C (60 min) with stirring, slow warming to room temp., stirring (room temp., 17 h); removement of volatiles (25-40°C, 12 Torr to 1E-5 Torr), NMR-monitoring, not isolated;