2,2'-azo-bisisobutyronitrile in neat (no solvent) mixt. of educts and AIBN warmed under Ar for 5 h at 64°C; crystd. (hexanes/C6H6); elem. anal.;

triethylamine in dichloromethane stirred soln. of Sn educt and (C2H5)3N treated dropwise with methanesulfonyl chloride at 0°C, kept at 0°C for 4 h; dild. with CH2Cl2, washed at 0°C with H2O, aq. HCl, satd. aq. NaHCO3, org. phase dried, evapd. (vac.), crystd. (hexanes/C6H6); elem. anal.;