Abstract Oximino sydnones 1a, b have been prepared and subjected to reaction with a variety of electrophilic reagents. The aldoxime reacted with all of the latter (except acetic anhydride) to give 3-(2-cyanophenyl) sydnone 1h. With acetic anhydride, both sydnone oximes formed the corresponding O-acetates li, m. Similarly, O-sulfonates 1l, k, j, respectively, were obtained by reaction of the ketoxime with benzene-, methane-and para- ...