iodine; triethylamine; triphenylphosphine in acetonitrile T=80 - 90°C; 6 h;

trimethylsilyl iodide in dichloromethane 0.166667 h; Ambient temperature; Yield given;

1: 89 percent / sodium borohydride / ethanol / 4 h / Heating 2: 77 percent / imidazole / dimethylformamide / 18 h 3: 1.) t-butyl-lithium, 2.) zinc bromide / 3.) <Pd(PPh3)4> / 1.) ether, -78 deg C, 45 min, 2.) -20 deg C, 1 h, 3.) THF, reflux, 2.5 h 4: tetrabutylammonium fluoride / tetrahydrofuran / 0.17 h / Heating 5: various solvent(s) / 5 h / Heating 6: 75 percent / chromium trioxide, celite / CH2Cl2; diethyl ether / 0 deg C, 20 deg C, 1.5 h View Scheme

in tetrahydrofuran T=0°C; 2.5 h;