1: 1-H-1,2,3,4,5,6,7-heptamethylindene With n-butyllithium in tetrahydrofuran; hexane T=25°C; Metallation; 4 h; 2: chloro-trimethyl-silane in tetrahydrofuran T=25°C; silylation; 15 h;

1.1: 84 percent / diethyl ether / Heating 2.1: 79 percent / p-TsOH / toluene / 5 h / Heating 3.1: butyllithiun / tetrahydrofuran; hexane / 4 h / 25 °C 3.2: 71 percent / tetrahydrofuran / 15 h / 25 °C View Scheme

1.1: 79 percent / p-TsOH / toluene / 5 h / Heating 2.1: butyllithiun / tetrahydrofuran; hexane / 4 h / 25 °C 2.2: 71 percent / tetrahydrofuran / 15 h / 25 °C View Scheme