Intended for students of intermediate organic chemistry, this text shows how to write a reasonable mechanism for an organic chemical transformation. The discussion is organized by types of mechanisms and the conditions under which the reaction is executed, rather than by the overall reaction. Worked problems are included with each mechanism, and "common error alerts" are strategically placed throughout the text. Each chapter is capped by a large problem set. The author draws on both his own research and the current literature to cover topics across the range of modern organic chemistry. The text includes a chapter on reactions mediated or catalyzed by transition metals, and covers emerging topics without short-changing more traditional material. Assuming a basic knowledge of organic chemistry, the text can be used in a formal course or by students working independently, and will be particularly useful as a study aid for qualifying examinations.