Challenging Problems in Organic Reaction Mechanisms explores the problems encountered in the study of the various facets of organic chemistry, including syntheses, reactions, reagents, and reaction mechanisms. Each problem describes the starting material, the conditions of the reaction, and the product, followed by the reference to the original publication. This permits the reader to solve the problem independently and then compare the results with those presented in the literature. The example problems are arranged in such a manner that each page is balanced. The utility of this collection has been enhanced by inclusion of, first, a ""compound index"" which allows rapid identification of rearrangements associated with a specific substrate; second, a ""reaction-type index"" which unifies reactions associated with a particular transition state and brings into focus the usefulness of Woodward-Hoffman notations in understanding bond formation and cleavage; and, finally, a ""problem classification index"". This work is of great value to organic chemists and researchers and organic chemistry teachers and students.