2,2,6,6-tetramethyl-piperidine; n-butyllithium in tetrahydrofuran; hexane T=-100°C; 6 h;

sulfuric acid in water; acetic acid 5 h; Heating;

1: With 2,2,6,6-tetramethyl-piperidine; n-butyllithium in tetrahydrofuran T=-78°C; 0.5 h; 2: 1-trifluoromethyl-4-bromobenzene in tetrahydrofuran T=-100°C; 6 h; 3: carbon dioxide With hydrogenchloride more than 3 stages;

borane-THF in tetrahydrofuran T=0 - 25°C; 16 h;