1: 2-[2-(trifluoromethyl)phenoxy]tetrahydro-2H-pyrane With n-butyllithium; N,N,N',N,-tetramethylethylenediamine in tetrahydrofuran; diethyl ether T=-20 - 20°C; 1.33333 h; 2: N,N-dimethyl-formamide in tetrahydrofuran; diethyl ether T=-30 - -20°C; 1 h;

acetic acid in methanol 8 h; Heating;

1.1: NaH / dimethylformamide / 1 h 1.2: 92 percent / dimethylformamide 2.1: n-butyllithium / tetrahydrofuran / 1 h / -78 °C 2.2: 81 percent / tetrahydrofuran / -78 - 20 °C 3.1: 45 percent / aq. AcOH / methanol / 8 h / Heating View Scheme

1.1: n-butyllithium / tetrahydrofuran / 1 h / -78 °C 1.2: 81 percent / tetrahydrofuran / -78 - 20 °C 2.1: 45 percent / aq. AcOH / methanol / 8 h / Heating View Scheme

T=20°C; Neat (no solvent);

N-bromosuccinmide in acetonitrile T=0°C; 1 h;