mercury dichloride; mercury(II) oxide in methanol; water a.) room temp., 5 h, b.) 50 degC, 1 h;

calcium carbonate in dichloromethane T=150 - 170°C; 0.25 h; Yield given;

1: 79 percent / I2, Ph3P, imidazole / CH2Cl2 / 5 h / 20 °C 2: 81 percent / 1.) BuLi / 1.) hexane, THF, -70 degC to 0 degC, 3 h, 2a.) THF, -78 degC, 1 h, 2b.) room temp., 12 h 3: 78 percent / HgCl2, HgO / methanol; H2O / 3 h / Heating 4: 87 percent / 1.) BuLi / 1.) hexane, THF, -70 degC to room temp., 3 h, 2.a) THF, -70 degC, 1 h, 2b.) room temp., overnight 5: 93 percent / 1.) BuLi / 1.) hexane, THF, HMPA, -78 degC to room temp. in 3 h, 2a.) -78 degC, 1 h, 2b.) room temp. overnight 6: 82 percent / HgCl2, HgO / methanol; H2O / a.) room temp., 5 h, b.) 50 degC, 1 h View Scheme

1: 78 percent / 1.) Mg / 1.) Et2O, 2.) Et2O, -78 degC, 2 h, then at room temp. overnight 2: 87 percent / 1.) BuLi / 1.) hexane, THF, -70 degC to room temp., 3 h, 2.a) THF, -70 degC, 1 h, 2b.) room temp., overnight 3: 93 percent / 1.) BuLi / 1.) hexane, THF, HMPA, -78 degC to room temp. in 3 h, 2a.) -78 degC, 1 h, 2b.) room temp. overnight 4: 82 percent / HgCl2, HgO / methanol; H2O / a.) room temp., 5 h, b.) 50 degC, 1 h View Scheme

1: 81 percent / 1.) BuLi / 1.) hexane, THF, -70 degC to 0 degC, 3 h, 2a.) THF, -78 degC, 1 h, 2b.) room temp., 12 h 2: 78 percent / HgCl2, HgO / methanol; H2O / 3 h / Heating 3: 87 percent / 1.) BuLi / 1.) hexane, THF, -70 degC to room temp., 3 h, 2.a) THF, -70 degC, 1 h, 2b.) room temp., overnight 4: 93 percent / 1.) BuLi / 1.) hexane, THF, HMPA, -78 degC to room temp. in 3 h, 2a.) -78 degC, 1 h, 2b.) room temp. overnight 5: 82 percent / HgCl2, HgO / methanol; H2O / a.) room temp., 5 h, b.) 50 degC, 1 h View Scheme

1: 87 percent / 1.) BuLi / 1.) hexane, THF, -70 degC to room temp., 3 h, 2.a) THF, -70 degC, 1 h, 2b.) room temp., overnight 2: 93 percent / 1.) BuLi / 1.) hexane, THF, HMPA, -78 degC to room temp. in 3 h, 2a.) -78 degC, 1 h, 2b.) room temp. overnight 3: 82 percent / HgCl2, HgO / methanol; H2O / a.) room temp., 5 h, b.) 50 degC, 1 h View Scheme

1: 78 percent / HgCl2, HgO / methanol; H2O / 3 h / Heating 2: 87 percent / 1.) BuLi / 1.) hexane, THF, -70 degC to room temp., 3 h, 2.a) THF, -70 degC, 1 h, 2b.) room temp., overnight 3: 93 percent / 1.) BuLi / 1.) hexane, THF, HMPA, -78 degC to room temp. in 3 h, 2a.) -78 degC, 1 h, 2b.) room temp. overnight 4: 82 percent / HgCl2, HgO / methanol; H2O / a.) room temp., 5 h, b.) 50 degC, 1 h View Scheme

1: 93 percent / 1.) BuLi / 1.) hexane, THF, HMPA, -78 degC to room temp. in 3 h, 2a.) -78 degC, 1 h, 2b.) room temp. overnight 2: 82 percent / HgCl2, HgO / methanol; H2O / a.) room temp., 5 h, b.) 50 degC, 1 h View Scheme