Etude par RMN 1H et 13C, de la stereochimie de [3] ferrocenophanols α,γ-disubstitues et de l'isomerisation conformationnelle des cations formes au cours de substitutions nucleophiles

Abstract

The analysis of the 1H and 13C spectra combined with INDOR experiments has allowed the identification of the predominant conformations of α,γ-disubstituted [3] ferrocenophanols. In trifluoracetic acid the hydroxylic group leaves the molecule from the less hindered side and the corresponding cation is obtained. The cation I′ resulting from the syn alcool is thermodynamically unstable and is transformed slowly into its stable conformational isomer I″. The stereochemistry of the cations was identified through analysis of the bridge group spectra and kinetics were quantitatively studied.