Book excerpt: More than any other branch of organic chemistry, synthesis has improved our understanding of the structure, dynamics, and transition of molecules. The availability of sophisticated tools and new techniques has made organic synthesis more challenging than ever for those in the field. This updated edition of the 1970 work highlights significant and intriguing synthetic achievements: their ingenuity in design, extent of stereochemical control, new reactions, and new reagents. Approximately 100 examples illustrate various aspects of organic synthesis, with particular emphasis on bond-making and bond-breaking, dissymetry, conformation, and stereoelectric considerations. Each describes the synthesis of a natural product or of an unusual or strained molecule. Numerous flow sheets and perspective structural formulas illustrate the force of arguments predicting the stereochemical outcome of important steps. Also included is a type-transformation index which highlights some less common reactions.