A New α-Iodination of Ketones Using Iodine-Ammonium Cerium(IV) Nitrate in Alcohol or Acetic Acid

The direct α-iodination of various ketones using iodine-ammonium cerium(IV) nitrate in acetic acid or alcohol gave the corresponding α-iodo ketones in high yields. The effect of cerium salt on the iodination of ketones, and the iodination of 5α-cholestan-3-one using several methods are also discussed. In the reaction of 3,3,5-trimethylcyclohexanone and unsymmetrical ketones, such as 2-hexanone and 2-heptanone, using methanol, ethanol, 1-propanol, and 2-propanol, the regioselective iodination product was obtained. In the case of bromination, the reaction of ketones with bromine and ammonium cerium(IV) nitrate also yielded the corresponding α-bromo ketones.