Cyclopentadienone cyclopentadienediyl dithioketals

Reaction of di-tert-butylcyclopentadiene with excess potassium tert-butoxid e in the presence of elemental sulfur leads to hitherto unknown cyclopentad ienes bridged by sulfur atoms via one or two dithioketal functionalities. T he X-ray crystal structures of compounds 1, 3, and 4 showing short inter- a nd intramolecular sulfur-sulfur interactions are reported. Analogous struct ures are assigned to compounds 2, 5, 6, and 7 by H-1, C-13 NMR, and mass sp ectroscopy. (C) 2000 Elsevier Science S.A. All rights reserved.