SYNTHESIS AND REACTIONS OF EXO-CAMPHORYLSULFONYLOXAZIRIDINE

The first example of an exo-camphorylsulfonyloxaziridine 4a was prepar ed by m-CPBA oxidation of camphor imine 9. This surprising result is d ue to the conformation of the imine which apparently prevents attack o f the peracid from the endo direction. Similar oxidations of all other camphorsulfonylimines result in the endo-oxaziridine exclusively. Asy mmetric oxidation of sulfides to sulfoxides and the alpha-hydroxylatio n of enolates by 4 can be interpreted in terms of open transition stat es where nonbonded interactions are minimized. These results support e arlier conclusions and predictions of the stereoselectivity and mechan isms of molecular recognition by the N-sulfonyloxaziridine class of ox idizing reagents.