Ring-opening of isoxazolidine nucleus: Competitive formation of α,β-enones and tetrahydro-1,3-oxazines

Article abstract of DOI:10.1016/0040-4020(95)00030-C

Treatment of isoxazolidine derivatives with methyl iodide, followed by simple heating with aqueous NaOH, gives rise to a competitive formation of α,β-enones and tetrahydro-1,3-oxazines. The ring-opening process is controlled by the stereochemistry of H₅ which represents the driving factor of two competitive reaction routes.