Synthesis and Dynamic Properties of Chiral Heptalenes

The enantiomerically pure valence isomers (+)- and (−)-1 and (+)- and (-)-2 are the first of their kind to be isolated. These compounds, which have nonplanar, cyclic conjugated π-electron systems and localized π-bonds in the ground state, are in dynamic equilibrium with one another. The kinetic data for the dynamic processes–ring inversion and bond shift–were also determined (R = H, Me).