1: With n-butyllithium; diisopropylamine in tetrahydrofuran T=-65 - -30°C; 2.5 h; 2: With boric acid trimethyl ester in tetrahydrofuran T=-65 - 10°C; 3: With water; ammonium chloride in tetrahydrofuran T=10°C; 0.5 h;