Ten 2,3‐disubstituted 4‐phenylsulfonyl isoxazolidines ( 3a‐j ) were prepared by 1,3‐dipolar cycloaddition reaction of substituted nitrones ( 1a‐j ) with phenyl vinyl sulfone ( 2 ). The reaction products were identified by means of IR, NMR, and MS data. In addition, the factors influencing on the electron ionization induced mass spectral fragmentation of the title products are discussed in detail.
