Mechanistic study of Wittig-Horner type condensation for unsymmetrical TTFsynthesis

The preparation of the DMBTTF 4 has been taken as a model to investigate th e mechanism of the pseudo-Homer condensation, method generally used to sele ctively prepare unsymmetrically substituted TTF derivatives. The results ob tained are described. They have allowed us to propose a mechanism of the re action together with a one pot experimental procedure leading to 4 in a ver y high yield. This protocol have been then extended to the preparation of a various series of unsymmetrical TTF. In most of the cases the yield obtain ed have been found higher than those given in the literature.