Route of triacylamine formation in the thermal conversion of 2,3,7-trioxa-5-azabicyclo[2.2.1]hept-5-enes investigated by nuclear magnetic resonance experiments

Thermal conversion of the typical aryl-, alkyl- and/or hydrogen-substituted oxazole endo-peroxides 2a–c into the triacylamines 5a–c proceeds by three subsequent rearrangements. The first leads to the dioxazoles 3a–c, which in the second stage rearrange into the imino anhydrides 4a–c. The latter collapse into the triacylamines 5a–c.