Na2S2O4 initiated free radical additions of polyfluoroalkyl halides to 4-pentenamides

The free radical additions of fluorine-containing halides to 4-pentenamides initiated by Na2S2O4 were investigated. Both polyfluoroalkyl iodide and ethyl iododifluoroacetate, gave rise to fluorine-containing gamma-butyrolactones as the main products while bromides such as ethyl bromodi-fluoroacetate gave the addition-reduction product. After steric, and stereo effects on reaction yields were studied using various substrates, it was concluded that the reactions of 4-pentenamides and polyfluoroalkyl iodides provide one alternative approach to prepare gamma-butyrolactones with fluorinated side chains. (C) 2007 Elsevier B.V. All rights reserved.