Use of deuteriation, endoperoxidation, and 2H nuclear magnetic resonance spectroscopy to demonstrate thermal [1,5] sigmatropic rearrangements in cycloalka-1,3-dienes

Abstract

The ²H n.m.r. spectra of the mixtures of endoperoxides obtained by photo-oxygenation of pyrolysed 1,4-diacetoxy-1,4-dideuteriocyclo-hexane, -heptane, and -octane demonstrate that 1.5-migrations of hydrogen and deuterium in the corresponding dideuteriated cycloalka-1,3-dienes proceed to equilibrium in less than 5 s at 480 °C.