catalyst: azobisisobutyronitrile in neat (no solvent) Irradiation (UV/VIS); equimolar amts. of alkyne and Me3SnH was irradiated with UV light (Hg high pressure lamp) under Ar in the presence of a catalytic amt. of AIBN for 11 h (IR and (1)H NMR monitoring); t-BuCH=C(SnMe3)2 to t-Bu(Me3Sn)C=CHSnMe3 ratio 98:2, total yield 34percent; the reaction mixt. was distilled under reduced pressure (b.p. 59°C/0.01 mm Hg); elem. anal. for the isomeric mixt., isomers were not sepd.;