“…Cyclopentadiene, 10 [72,73], and indene, 11 [74], were easily C-alkylated in the presence of aqueous NaOH and triethylbenzylammonium chloride. Using dihaloalkanes as alkylating agents, high yields of a very wide variety of spiro C-alkylations of cyclopentadiene were obtained when using nonpolar solvents.…”