1: With n-butyllithium; zirconocene dichloride in tetrahydrofuran; hexane T=-78 - 20°C; Cyclization; 1 h; 2: With iodine in tetrahydrofuran T=20°C; Iodination; 3 h;

1: (3Z,5Z)-4,5-diethyl-3,6-diiodoocta-3,5-diene With tert.-butyl lithium in tetrahydrofuran T=-64 - -52°C; 1 h; 2: methyl iodide in tetrahydrofuran T=20°C; 1.5 h;

1: With tert.-butyl lithium in tetrahydrofuran cooling; 2: With methanol in tetrahydrofuran