The pyrolysis of pinanes. IX. On the mechanism of [_σ2+_σ2] cyclo-reversion in pinane thermolysis

Abstract

The formation of (E)- and (Z)-3,7-dimethylocta-1,6-dienyl acetate (8) and (9) from pyrolysis of endo-10β-pinan-7-yl acetate (5b) is consistent with the intermediacy of the 1,4-biradical (18) or with the reaction proceeding in part by a concerted [_σ2_S + _σ2_a] process.