1: n-amyl iodide; CpMgCl in tetrahydrofuran T=20 - 60°C; 4.08333 h; Inert atmosphere; 2: With n-butyllithium in hexanes; diethyl ether T=20°C; 0.666667 h; Inert atmosphere; 3: ZrCl4(tetrahydrofuran)2 in hexanes; diethyl ether T=20°C; 2.5 h; Inert atmosphere;