1: With n-butyllithium in tetrahydrofuran T=-78°C; 4.5 h; 2: With potassium hydroxide in tetrahydrofuran; water T=20°C; 0.166667 h; 3: With sulfuric acid; water in isopropyl alcohol T=55 - 60°C; pH=3 - 4; 2 h;