sodium in tetrahydrofuran; benzene byproducts: NaCl; to metallic Na in THF t-BuC5H5 added at -20°C; after 2 h n-BuCl in THF added dropwise; stirred for 10 h; NaCl filtered off; TiCl4 in THF/benzene added at 0°C to the filtrate; stirred for 3 h at -20°C; satd. with dry HCl; solvent evapd. in vacuo; residue extd. (HCl-satd. CHCl3); recrystd. (CHCl3); elem. anal.;