in diethyl ether N2-atmosphere;;

in tetrahydrofuran; diethyl ether soln. of dilithio reagent (ether) was dropwise added to soln. of diphenyltin dichloride (THF), 2 h, stirred under N2 at reflux; ether was remeved in vac., dichloromethane was added, and filtered, concd. and abs. ethanol was added, pptd. by cooling with dry ice; recrystd.from dichloromethane-ethanol; isolated the butadienyl-diphenyltin dichloride; elem. anal.;

in tetrahydrofuran; cyclohexane (Ar), PhLi in cyclohexane added at -80°C to a THF soln. of Sn complex, warmed to room temp. over 3.5 h; evapd., filtered, chromy.(SiO2 - hexane/ethyl acetate 10:1);

in not given byproducts: Me2SnCl2; crystd. at -35°C from CH2Cl2;

lithium in diethyl ether byproducts: PhLi; Sn-compound reacted with excess Li in ether at room temp., CH3I added;

Cl2 in tetrachloromethane byproducts: 1,4-dichloro-1,2,3,4-tetraphenylbutadiene; Cl2 was stirred with Sn compd. at -78°C for 2 h (N2); warming toroom temp.; evapn, treating with CH2Cl2, filtration;