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;

toluene-4-sulfonic acid in toluene Dehydration; 5 h; Heating;

sodium dithionite; iodine in diethyl ether

1: 84 percent / diethyl ether / Heating 2: 79 percent / p-TsOH / toluene / 5 h / Heating View Scheme