carbon monoxide; palladium on activated charcoal; triphenylphosphine; 1,4-di(diphenylphosphino)-butane in ethylene glycol dimethyl ether T=100°C; P=5168 Torr; 24 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

carbon monoxide; palladium on activated charcoal; triphenylphosphine; 1,4-di(diphenylphosphino)-butane in ethylene glycol dimethyl ether T=100°C; P=30400 Torr; 24 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

N,N,N',N,-tetramethylethylenediamine; zinc trifluoromethanesulfonate; 1,8-diazabicyclo[5.4.0]undec-7-ene in tetrahydrofuran T=25°C; Horner-Wadsworth-Emmons reaction; 12 h;

pyridine