Nitrones and oxaziridines. XXI electronic substituent effects in nitrone cycloadditions to highly Polarized Alkenes
DSC Black, RF Crozier, ID Rae
Australian Journal of Chemistry | Published : 1978
1,3-Dipolar cycloaddition reactions of nitrones-particularly N-(2'- pyridylmethylene)aniline N-oxide-with arylmethylene cyanoacetates exclusively yield 4,4-disubstituted isoxazolidines, identifiable by 1H n.m.r, spectroscopy and isolable in some cases. Comparative kinetic experiments provide evidence for at least non-synchronous addition via a dipolar intermediate or possibly even two-step addition via a discrete zwitterionic intermediate.