The titanium promoted cyclization of the diketone ButC(O)CH2CH2CH2C(O)Bu(t), 1, affords 1,2-di-tert-butyl-1,2-cyclopentanediol, 2. Further reaction of 2 with POCl3 in hot pyridine results in dehydration to give the new vicinally di-tert-butyl-substituted cyclopentadiene, 3, which exists mainly as the 1,5-di-tert-butylcyclopentadiene tautomer 3b. As with other cyclopentadienes, 3 reacts cleanly with Bu(n)Li to give the corresponding lithium cyclopentadienide, 4, which in turn reacts with FeCl2.2THF to form 1,1',2,2'-tetra-tert-butylferrocene, 5. The structure of 5 has been confirmed by single crystal X-ray crystallography: Crystal data for 5 with Mo Kalpha (lambda = 0.7107 angstrom) radiation at 246 K: C26H42Fe, a = 16.135(3) angstrom, b = 8.416(1) angstrom, c = 16.800(3) angstrom, orthorhombic space group Cmca (No. 64), Z = 4, R = 0.0543, R(w) = 0.0734.