Regioselective ring opening of β-phenylglycidate and aziridine-2-carboxylates with N-alkylhydroxylamines: synthesis of isoxazolidinones

A simple and efficient method for the synthesis of 4-hydroxy or 4-alkylamino isoxazolidin-3-ones and 4-hydroxy isoxazolidin-5-ones is described. The synthesis involved the ring opening of ethyl β-arylglycidates or ethyl N-alkylaziridine-2-carboxylates by free N-alkylhydroxylamines or hydroxylamine anions, followed by cyclization to give the title isoxazolidinones in moderate to good yields.