The control of reactivity to achieve specific syntheses is one of the overarching goals of organic chemistry. Since the publication of the third edition of this text, major advances have been made in the development of efficient methods, particularly catalytic processes, and in means for control of reaction stereochemistry. This volume assumes a level of familiarity with structural and mechanistic concepts comparable to that in the companion volume, Part A, Structures and Mechanisms . Together, the two volumes are intended to provide the advanced undergraduate or beginning graduate student in chemistry with a sufficient foundation to comprehend and use the research literature in organic chemistry.