n-butyllithium; carbon monoxide in tetrahydrofuran under N2, amine, THF, BuLi stirred (-10°C, 5 min), cooled (-78°C), stream of CO (10 ml/min) bubbled through soln. (atmospheric pressure, 30 min, yellow soln.), quenched with ClSnR3 (neat or THF soln.), stiired (2 h), warmed (room temp.); addn. to Et2O, washed (aq. KF, 3 times, then distd. H2O, 5 times), ether layer dried (MgSO4), concn. (oil), flash chromy. (light petroleum-ether (1:1)); elem. anal.;

tetrakis(triphenylphosphine) palladium(0) in toluene Heating;

tetrakis(triphenylphosphine) palladium(0) in toluene Heating;