in diethyl ether T=0 - 20°C; 18 h;

1: (E/Z)-1-Fluoro-2-phenylethylene With lithium diisopropyl amide in tetrahydrofuran; hexane T=0°C; Metallation; 0.5 h; 2: butyraldehyde in tetrahydrofuran; hexane T=0 - 20°C; Substitution; Dehydrofluorination; 2.5 h;

mercury(II) diacetate; sodium hydrogencarbonate 1) TFA, r.t., overnight; Yield given. Multistep reaction;