The　Friedel-Crafts　type　alkylation　of　C2-tethered　thiophenes　has　been　reported　to　be　nonregioselective.　Taking　advantage　of　the　highly　regioselective　5-exo-trig　spirocyclization　of　an　electrochemically　generated　amidyl　radical,　we　have　unraveled　an　electrochemical　dearomative　spirocyclization　of　N-acyl　thiophene-2-sulfonamides.　Various　nucleophilic　agents,　including　carboxylates,　alcohols,　and　fluoride,　are　readily　incorporated　to　afford　the　remotely　functionalized　spirocyclic　dihydrothiophenes,　and　their　novel　spirocy-clic　scaffolds　have　been　shown　to　exhibit　promising　antitumor　activities.