BRIDGED FERROCENES .4. INTRAMOLECULAR CYCLIZATION OF FERROCENE DERIVATIVES CONTAINING ALPHABETA-UNSATURATED CARBONYL FUNCTIONS

The synthesis of [5]ferrocenophane derivatives from non-bridged precursors has been studied. Intramolecular cyclization of 1,1′-diacryloylferrocene and related compounds has been shown to occur under catalytic hydrogenation conditions and in the presence of hydrogen chloride or sodium ethoxide. The mechanism of the reaction between 1-(α-chlorovinyl)-1′-(α-chloro-β-formylvinyl)ferrocene and phosphorus oxychloride in dimethylformamide has been investigated. A number of new [5]ferrocenophane derivatives have been synthesized by modification of the bridging group in the compounds prepared by the above routes. © 1969.