The direct oxidation reaction of isoxazolidines plays an important role in organic chemistry, leading to the synthesis of biologically active compounds. In this paper, we report a computational mechanistic study of RuO4-catalyzed oxidation of differently N-substituted isoxazolidines 1a-c. Attention was focused on the endo/exo oxidation selectivity. For all the investigated compounds, the exo attack is preferred to the endo one, showing exo percentages growing in parallel with the stability order of transient carbocations found along the reaction pathway. The study has been supported by experimental data that nicely confirm the modeling results.
Keywords: 3-isoxazolidinone; DFT calculations; chemoselectivity; oxidation; ruthenium tetroxide.