A representative series of homopropargylic sulfonamides 19 and 22b have been found to undergo smooth 5-endo-dig cyclisation upon exposure to excess iodine in acetonitrile containing potassium carbonate. The resulting 4-iodo-2, 3-dihydropyrroles 23 readily react with two equivalents of DBU in DMF at 20° C to give the corresponding β-iodopyrroles 24 and 26 in excellent yields by the elimination of toluene-p-sulfinic acid. Use of less than two ...