The Synthesis of Highly Substituted Isoxazoles by Electrophilic Cyclization: An Efficient Synthesis of Valdecoxib
Jesse P. Waldo and Richard C. Larock*
*Department of Chemistry, Iowa State University, Ames, Iowa 50011, Email: larockiastate.edu
J. P. Waldo, R. C. Larock, J. Org. Chem., 2007, 72, 9643-9647.
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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.
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J. P. Waldo, R. C. Larock, Org. Lett., 2005, 7, 5203-5205.