triethyl borane; tert.-butyl lithium; bis-triphenylphosphine-palladium(II) chloride 1.) THF, pentane, hexane, r.t., 1 h; -20 deg C, 1 h, 2.) THF, CO, 15 atm., 60 deg C, 40 h; Yield given. Multistep reaction. Yields of byproduct given;

triethyl borane; tert.-butyl lithium; bis-triphenylphosphine-palladium(II) chloride 1.) THF, pentane, hexane, r.t., 1 h; -20 deg C, 1 h, 2.) THF, 15 atm., 60 deg C, 40 h; Yield given. Multistep reaction. Yields of byproduct given;