Sodium dithionite initiated regio- and stereoselective radical addition of polyfluoroalkyl iodide with norbornene analogs

Sodium dithionite initiated free-radical addition of norbornene and its derivatives with polyfluoroalkyl iodides was investigated. In all the cases the addition of RF was stereoselective at exo-position and the predominant configuration of products was trans. Norbornene with a high steric hindered group in the 2-endo-position gave 6-exo-RF-5-endo-iodo adduct and deiodined product. Fluoroalkylation-lactonization occurred in the addition of norbornene-2-endo-carboxylic acid with RFI to afford fluorinated γ-lactone products.