The FeCl₃-mediated reaction of alkynols with iodine resulted in intramolecular addition of hydroxyl to alkyne to produce a wide range of iodocycloenol ethers in good to excellent yields (63%～90%) under mild reaction conditions. On the other hand, 1,2-diiodides were obtained generally in good yields (15%～88%) when propargyl alcohols were reacted with iodine in the same condition. The advantages of our procedure include a decreased amount of iodine (0.5 equiv.) as well as short reaction time (3 h). The broad scope, mild reaction conditions, and experimental ease of this transformation have made it a valuable alternative to current available methods for the preparation of iodocycloenol ethers or 2,3-diiodoalkenols.

Key words: intramolecular iodoetherification, iron trichloride, alkynol, 2,3-diiodoalkenol