n-butyllithium in tetrahydrofuran; hexane 1.) -78 deg C, 1 h; 2.) 15 h room temperature;

1: With n-butyllithium in tetrahydrofuran T=-78°C; Wittig-Horner Reaction; 2: With bromine in tetrachloromethane 3: With sodium hydroxide in ethanol; water

1.1: n-butyllithium / diethyl ether; hexane / 5 h / -80 - 0 °C / Inert atmosphere 2.1: n-butyllithium / tetrahydrofuran; hexane / 2 h / -80 °C / Inert atmosphere 2.2: 1 h / 0 °C / Inert atmosphere 2.3: 1 h / 20 °C / Inert atmosphere View Scheme

bromine; sodium hydrogencarbonate 1.) CCl4, reflux, 5 h; 2.) acetone, reflux, 7 h; Yield given. Multistep reaction;