Abstract PhSCF 2 TMS was utilized as a useful gem-difluoromethylene building block for the synthesis of gem-difluoromethylenated spiro-γ-butyrolactones. The radical cyclization of γ- alkenyl-γ-gem-difluoro (phenylsulfanyl) methyl-γ-butyrolactones provided gem- difluoromethylenated spiro-γ-butyrolactones.