Stereoselective cycloaddition–lactonization reaction of 2-allyl-4-pentenoic acids with polyfluoroalkyl iodides. An efficient synthesis of polyfluoroalkyl-containing bicyclolactone derivatives

Polyfluoroalkyl-containing bicyclolactones were synthesized via the sodium dithionite-initiated cycloaddition–lactonization reaction of 2-allyl-4-pentenoic acids and polyfluoroalkyl iodides. The chemo- and stereo-selectivity of the cycloaddition–lactonization reaction strongly depended on the space hindrance of 2-substituent in 2-allyl-4-pentenoic acids. The reaction was believed to proceed through a tandem free radical addition-lactonization process.