1: 1) n-BuLi / THF, 1) - 78 deg C, 20 min, 2a) up to r.t., 4 h, 2b) reflux, 24 h 2: KF, triglyme View Scheme

1: diisopropyl(carboethoxyfluoromethyl)phosphonate With n-butyllithium in tetrahydrofuran T=-78°C; 2: trifluoroacetic acid chloride in tetrahydrofuran T=-78 - 20°C; 3: anhydrous potassium trimethylsilanolate in tetrahydrofuran T=20°C; 10 h; Further stages.;

1: diisopropyl(carboethoxyfluoromethyl)phosphonate With n-butyllithium in tetrahydrofuran T=-78°C; 0.333333 h; 2: trifluoroacetic acid trimethylsilyl ester in tetrahydrofuran T=-78 - 20°C; 3: With hydrogenchloride in tetrahydrofuran Further stages.;

1: diisopropyl(carboethoxyfluoromethyl)phosphonate With n-butyllithium in tetrahydrofuran T=-78°C; 2: trifluoroacetic acid chloride in tetrahydrofuran T=-78 - 20°C; 3: anhydrous potassium trimethylsilanolate in tetrahydrofuran T=20°C; 10 h; Further stages.;