Trifluoromethyl (CF3)-substituted donor–acceptor norbornadiene (NBD) derivatives were synthesized. The photoisomerization of CF3-NBD derivatives proceeded smoothly. The thermal stability of quadricyclane (QC) derivatives obtained from CF3-NBD derivatives was examined, and it was found that the CF3 group increased the thermal stability of the QC derivatives. Furthermore, CF3-NBD derivatives exhibited efficient fatigue resistance.
Polymers containing trifluoromethyl. (CF3)-substituted donor-acceptor NBD moieties in the side chain or in the main chain were synthesized by substitution or addition of a CF3-NBD-carboxylic acid derivative or by polycondensation of a CF3-NBD-dicarboxylic acid derivative. The photoisomerization of the NBD moieties in these polymers proceeded very smoothly to give the corresponding QC moieties. Furthermore, the NBD moieties exhibited efficient fatigue resistance.
[3,3] Sigmatropic rearrangements of benzyl vinyl ethers. Model studies directed toward the total synthesis of cephalotaxine
作者:Stanley Raucher、David S. Jones、Ronald E. Stenkamp