A novel bromolactonization reaction using racemic 2-bromo-5-isobutyl-5-methylhydantoin

By using recemic 3-bromo-5-isobutyl-5-methylhydantoin (3a') in dry N, N-dimethylformamide which is a model reagent for asymmetric bromolactonization, bromolactonization of a series of olefinic acids was carried out to furnish corresponding bromolactones in moderate yields.