Benzoxathiazine　dioxide,　as　a　bioisostere　of　the　clinically　widely　used　diazoxide,　exhibits　interesting　biological　activity.　However,　limited　success　has　been　achieved　in　terms　of　its　concise　and　direct　synthesis.　We　report　herein　a　facile　electrochemical　migratory　cyclization　of　N-acylsulfonamides　to　access　a　diverse　array　of　benzoxathiazine　dioxides.　The　inclusion　of　electrochemistry　is　crucial　for　realizing　such　a　novel　transformation,　which　is　substantiated　both　by　the　experiments　and　density-functional-theory　calculations.