sodium amalgam in methanol T=0°C; 4.25 h;

1: (cis-3,7-Dimethyl-2,6-octadienyl) phenyl sulfide With lithium in diethyl ether T=3 - 6°C; 2 h; 2: carbon dioxide

Rh6(CO)12; tetrabutyl-ammonium chloride; water; triethylamine in dimethyl sulfoxide T=50°C; P=15200 Torr; 10 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

barium 1.) THF, -78 deg C, 30 min, 2.) THF, -78 deg C; Yield given. Multistep reaction;

1: PBr3 / diethyl ether / 0.17 h / 0 °C 2: 93 percent / dimethylformamide / 24 h / Ambient temperature 3: 1.) n-BuLi / 1.) THF, hexane, 5 min, -75 deg C; -75 deg C to -45 deg C, 15 min, 2.) -95 deg C, 4 h; -95 deg C to -65 deg C, 1 h 4: 96 percent / Na-Hg / methanol / 4.25 h / 0 °C View Scheme

1: 93 percent / dimethylformamide / 24 h / Ambient temperature 2: 1.) n-BuLi / 1.) THF, hexane, 5 min, -75 deg C; -75 deg C to -45 deg C, 15 min, 2.) -95 deg C, 4 h; -95 deg C to -65 deg C, 1 h 3: 96 percent / Na-Hg / methanol / 4.25 h / 0 °C View Scheme

1: 1.) n-BuLi / 1.) THF, hexane, 5 min, -75 deg C; -75 deg C to -45 deg C, 15 min, 2.) -95 deg C, 4 h; -95 deg C to -65 deg C, 1 h 2: 96 percent / Na-Hg / methanol / 4.25 h / 0 °C View Scheme