A large number of functionally substituted 2-alkyn-1-one O-methyl oximes have been cyclized under mild reaction conditions in the presence of ICl to give the corresponding 4- iodoisoxazoles in moderate to excellent yields. The resulting 4-iodoisoxazoles undergo various palladium-catalyzed reactions to yield 3, 4, 5-trisubstituted isoxazoles, including valdecoxib.
