A theoretical investigation of through-space interactions. Part 3. A semiempirical study of the Cope rearrangement in singly annellated semibullvalenes

Abstract

A series of singly annellated semibullvalenes has been studied by semiempirical (MNDO, AM1, PM3) calculations. The Cope rearrangement is examined in each case. In the ethano-annellated system 3 the groundstate for the molecule is predicted to be the symmetrical homoaromatic species 3c. This provides another example of the elusive class of neutral homoaromatics.