Theoretical studies on valence tautomerism between 1,6-methano[10]annulene and tricyclo[4.4.1.01,6]undeca-2,4,7,9-tetraene

Abstract

The energy profiles for the valence-tautomeric equil. I.dblharw.II and III.dblharw.IV were detd. by ab initio calcns. The energy barrier for the forward and back reaction for I.dblharw.II was 7.3 and 2.3 kcal/mol; these values are .apprx.3 kcal/mol smaller than those for the III.dblharw.IV equil.