Nonstatistical dynamics in the thermal Garratt-Braverman/[1,5]-H shift of one ene-diallene: an experimental and computational study.

A mechanistic study of the thermal Garratt-Braverman/[1,5]-H shift of ene-diallene 6 leading to alkenes (E)-8 and (Z)-8 is reported. The product ratio was found to be temperature-independent and does not agree with the computed energy barriers (i.e., TS2E(⧧) and TS2Z(⧧)). On the basis of experimental and DFT computational results, we propose a mechanism that is strongly controlled by nonstatistical dynamic effects.