INDO calculations on the sigmatropic [1, 5] H-Shift in 1,3-cyclohexadiene and 1,3,5-cycloheptatriene A homo-cyclopentadienyl transition state model

INDO calculations have been performed for the activated complex of the 1, 5] H.-shift in 1,3-cyclohexadiene and 1,3,5-cycloheptatriene. During the migration in the cyclohexadiene system a homoconjugation was calculated between the carbon atoms C₁ and C₅. For cycloheptatriene it could be demonstrated that one double bond does not participate in the reaction. Activation enthalpies are related to (homo)conjugation in the transition state of the reaction for cyclic conjugated dienes and trienes. The electron density on the migrating hydrogen can be related to the electron affinity of the ring system in the transition state./p]