1: With N,N,N',N',N'',N''-hexamethylphosphoric triamide; copper(l) iodide in tetrahydrofuran T=-78 - 20°C; 1 h; Inert atmosphere; 2: With tetrabutyl ammonium fluoride in tetrahydrofuran T=20°C; 0.5 h; Inert atmosphere;