titanium tetrachloride in dichloromethane T=-78°C; 0.0833333 h;

n-butyllithium; chloro-trimethyl-silane in tetrahydrofuran; hexane

1: 1.) n-BuLi / 1.) THF, hexane, -78 deg C, 1 h; 2.) -78 deg C, 1 h; room temp., overnight 2: 87 percent / titanium(IV) chloride / CH2Cl2 / 0.08 h / -78 °C View Scheme