Abstract The tin-containing sulfide Me 3 Sn (CH 2) 3-SC 6 H 5 CH 3-4 obtained by photoaddition of 4-toluene-thiol to allyltrimethyltin was oxidized with hydrogen peroxide to synthesize the tin-containing sulfone Me 3 Sn (CH 2) 3-SO 2-C 6 H 4 CH 3-4, the tin and sulfur atoms in which are separated by a trimethylene bribge. Treatment of the sulfone with butyllithium gave a first tin-containing lithium salt having a red-brown color. The exchange ...