Annual Reports in Organic Synthesis 2004 provides an organized annual review of synthetically useful information that proves beneficial to organic chemists, both specialists and nonspecialists in synthesis. Information appears as promptly as possible after the close of the abstracting period and is presented in an organized manner. Chapters I to III are organized by reaction type. Chapter IV deals with methods of synthesizing heterocyclic systems. Chapter V covers the use of protecting groups. Chapter VI deals with those synthetically useful transformations that do not fit easily into the first three chapters. In Chapter VII, the reviews have been divided into sections to help the reader to quickly find a review on a specific topic.