pyrrolidine; tetrakis(triphenylphosphine) palladium(0) T=82°C; 16 h;

carbon monoxide; bis(dibenzylideneacetone)-palladium(0) in tetrahydrofuran T=20°C; P=760.051 Torr; 24 h;

1: 85 percent / 18-crown-6 ether / acetonitrile / 288 h / Ambient temperature 2: 2.) hydrochloric acid / !:) ethyl ether, THF, reflux, 2.5 h, 2.) reflux, 3 h 3: 69 percent / ethanol / 2 h / Heating 4: 21 percent / tert-butyllithium / pentane; tetrahydrofuran / 1.) -78 deg C, 24 h, 2.) room temperature 5: 44 percent / 550 °C / 0.1 Torr View Scheme

1: 40 percent / N-bromosuccinimide, benzoyl peroxide / CCl4 / 4.5 h / Heating 2: 85 percent / 18-crown-6 ether / acetonitrile / 288 h / Ambient temperature 3: 2.) hydrochloric acid / !:) ethyl ether, THF, reflux, 2.5 h, 2.) reflux, 3 h 4: 69 percent / ethanol / 2 h / Heating 5: 21 percent / tert-butyllithium / pentane; tetrahydrofuran / 1.) -78 deg C, 24 h, 2.) room temperature 6: 44 percent / 550 °C / 0.1 Torr View Scheme

1: 25 mg / tetrahydrofuran / 0.17 h / -78 °C 2: 40 percent / N-bromosuccinimide, benzoyl peroxide / CCl4 / 4.5 h / Heating 3: 85 percent / 18-crown-6 ether / acetonitrile / 288 h / Ambient temperature 4: 2.) hydrochloric acid / !:) ethyl ether, THF, reflux, 2.5 h, 2.) reflux, 3 h 5: 69 percent / ethanol / 2 h / Heating 6: 21 percent / tert-butyllithium / pentane; tetrahydrofuran / 1.) -78 deg C, 24 h, 2.) room temperature 7: 44 percent / 550 °C / 0.1 Torr View Scheme

1: 15 percent / tetrahydrofuran / 48 h / Heating 2: 40 percent / N-bromosuccinimide, benzoyl peroxide / CCl4 / 4.5 h / Heating 3: 85 percent / 18-crown-6 ether / acetonitrile / 288 h / Ambient temperature 4: 2.) hydrochloric acid / !:) ethyl ether, THF, reflux, 2.5 h, 2.) reflux, 3 h 5: 69 percent / ethanol / 2 h / Heating 6: 21 percent / tert-butyllithium / pentane; tetrahydrofuran / 1.) -78 deg C, 24 h, 2.) room temperature 7: 44 percent / 550 °C / 0.1 Torr View Scheme

T=550°C; P=0.1 Torr;

t-Bu-XantPhos; dichloro bis(acetonitrile) palladium(II); potassium carbonate; cesium fluoride in toluene T=100°C; 20 h; Inert atmosphere;

(PPh3P)2PdCl2; triethylamine; triphenylphosphine 1 h; Ambient temperature;

1: 69 percent / ethanol / 2 h / Heating 2: 21 percent / tert-butyllithium / pentane; tetrahydrofuran / 1.) -78 deg C, 24 h, 2.) room temperature 3: 44 percent / 550 °C / 0.1 Torr View Scheme