1: 1,1-Dibromo-4-methyl-1-pentene With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 1 h; 2: chloroformic acid ethyl ester in tetrahydrofuran; hexane T=20°C;

1: With lithium hexamethyldisilazane in tetrahydrofuran T=-78°C; 0.75 h; Inert atmosphere; 2: With trifluoromethylsulfonic anhydride in tetrahydrofuran T=-78 - 20°C; Inert atmosphere; 3: With ammonium chloride in tetrahydrofuran; water T=20°C;

T=260 - 280°C; P=0.4 Torr; 3.5 h;

1: benzene / 12 h / 20 °C 2: 2.3139 g / 3.5 h / 260 - 280 °C / 0.4 Torr View Scheme

(i) LDA, Et2O, (ii) /BRN= 1236431/, THF, (iii) I2; Multistep reaction;

1: 48 percent / tetrahydrofuran / 1.5 h / cooling 2: 93 percent / KOH / methanol; H2O / 7 h / Heating View Scheme