Ring-Opening of Substituted Isoxazolidines: One-Pot Synthesis of Indenes

Article abstract of DOI:10.1016/S0040-4020(01)81879-2

High yield conversion of 3,5,5-triarylisoxazolidines into indene derivatives has been achieved by 4 h refluxing in aq.H2SO4.The rearrangement pathway is interpretable on the basis of a ring-opening process where the crucial step is the protonation of the oxygen atom of the isoxazolidine nucleus.MNDO calculations performed on N,N,O-trimethylhydroxylamine chosen as a model system support the proposed mechanism.