The　incorporation　of　sulfonyl　fluoride　groups　into　molecules　has　been　proven　effective　in　enhancing　their　biological　activities　or　introducing　new　functions.　Herein,　a　transition-metal-free　and　visible-light-mediated　radical　tandem　cyclization　of　unsaturated　carboxylic　acid　is　reported.　This　affords　a　facile　access　to　FSO2-functionalized　gamma-lac-tones　efficiently,　which　are　critical　structural　motifs　widely　present　in　biologically　active　molecules.