
%0 Journal Article
%A Black, DSC 
%A Crozier, RF 
%A Rae, ID 
%T Nitrones and oxaziridines. XXI. Electronic substituent effects in nitrone cycloadditions to highly polarized alkenes
%J Australian Journal of Chemistry
%D 1978/10/01
%V 31
%N 10
%P 2239-2246
%K 
%R https://doi.org/10.1071/CH9782239
%U https://www.publish.csiro.au/paper/CH9782239 
%X 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. 
