1: With n-butyllithium; diisopropylamine in tetrahydrofuran; hexane T=-25 - -10°C; 0.5 h; 2: 1-(4-fluorophenyl)-2-phenyl-1-ethanone in tetrahydrofuran; hexane T=-78 - -60°C; 1 h; 3: 2-bromo-4-methyl-3-oxo-pentanoic acid phenylamide in tetrahydrofuran; hexane T=-78 - 15°C; 1.5 h;