1: 1.) BuLi / 1.) THF, hexane, from -30 deg C to -20 deg C, 1.5 h, 2.) THF, hexane, from -78 deg C to RT 17 h 2: 88.3 percent 3: 98 percent / CuO, CuCl2 / acetone / 1.5 h / Heating 4: 71 percent / NaOH / methanol / Heating View Scheme

titanium tetrachloride in nitromethane T=-18 - 20°C; 24 h;

N,N-dioctyl-1-octylamine; bromine; tin(IV) chloride in 1,2-dichloro-ethane T=-17 - 25°C; 3.25 h;

copper(ll) bromide in ethyl acetate 0.75 h; Heatingvar. solvents; Product distribution;

lithium carbonate; lithium bromide in N,N-dimethyl-formamide T=150°C; 1 h;

1: 1.) BuLi / 1.) THF, hexane, from -30 deg C to -20 deg C, 1.5 h, 2.) THF, hexane, from -78 deg C to RT 17 h 2: 88.3 percent 3: 98 percent / CuO, CuCl2 / acetone / 1.5 h / Heating View Scheme