X-ray structural analysis for the prediction on the nature of the retro DielsAlder pathway: Concerted or stepwise. structural studies on nitrosobenzene cycloadducts

Abstract

Crystal structures of nitrosobenzene cycloadducts 57 reveal structural effects consistent with the early stages of the retro DielsAlder fragmentation. There is a clear differentiation between the structure parameters of cycloadduct 5, which reacts by a concerted synchronous pathway and that of cycloadduct 6, which must react by a two-step pathway. Based on these data, cycloadduct 7 is predicted to react by a highly asynchronous or two-step pathway. © 2010 CSIRO.