1: 92 percent / acetonyltriphenylphosphonium bromide / CH2Cl2; methanol / 0.17 h / 20 °C 2: 99 percent / poly-p-styryl-acetonyltriphenylphosphonium bromide / CH2Cl2 / 3 h / 20 °C View Scheme

titanium tetrachloride in tetrahydrofuran T=-78°C; 6 h;

poly-p-styryl-acetonyltriphenylphosphonium bromide in dichloromethane T=20°C; 2 h;

potassium hydroxide

1: hydrogen chloride 2: ethanolic KOH-solution View Scheme

1.1: n-BuLi; TMEDA / diethyl ether; hexane; cyclohexane / -60 - 20 °C 1.2: 72 percent / diethyl ether; hexane; cyclohexane / 16 h / -70 - 20 °C 2.1: 99 percent / diethyl ether; cyclohexane / 24 h / -80 - 20 °C 3.1: 88 percent / pyridinium p-toluenesulfonate / ethanol; CH2Cl2 / 4 h / 65 °C View Scheme