tert.-butyl lithium in diethyl ether -78 -> 25 deg C;

diisobutyl-aluminum chloride in various solvent(s) T=50°C; 12 h;

1: 93 percent / 1.) n-BuLi / tetrahydrofuran; hexane / 1.) -78 deg C, 1 h; 2.) rt, 6 h 2: 90 percent / LiBr / acetone / 12 h / 25 °C 3: 1.) Cl(H)ZrCp2; 2.) AlCl3 / 1.) benzene, 25 deg C, 12 h; 2.) CH2Cl2, 0 deg C, 1 h View Scheme

1.1: methanol / 4.5 h / 20 °C 2.1: NaHCO3 / methanol 2.2: 180 °C View Scheme