Treatment of electrostatic effects within the molecular mechanics method. 3. Double bonds and conjugated systems

The previously developed general method (IDME), which includes calculation of electrostatic and solvation effects on conformational equilibria, has been extended to molecules containing double bonds and conjugated systems. It was applied in connection with MM2 studies to the calculation of the charge distributions and dipole moments, and to the conformational energies of some β‐substituted cyclohexenes, exo ‐methylenecyclohexanes and benzocycloheptenes. Conformational equilibria and dipole moments were well calculated. It was concluded that electrostatic interactions do not play a major role in determining conformational preferences in these compounds. On the other hand, the energies of the preferred conformations of the ten‐membered ring in ( E )‐3β‐acetoxy‐5,10‐seco‐1(10)‐cholesten‐5‐one are poorly calculated without the IDME procedure, and fairly well with it.