Organic Chemistry, 13th edition provides a comprehensive, yet accessible, treatment of all the essential organic chemistry concepts, with emphasis on relationship between structure and reactivity in the subject. The textbook includes all the concepts covered in a typical organic chemistry textbook but is unique in its skill-development approach to the subject. Numerous hands-on activities and real-world examples are integrated throughout the text to help students understand both the "why" and the "how" behind organic chemistry. This International Adaptation offers new and updated content with improved presentation of all course material. It offers new material on several topics, including the relevance of intermolecular forces in the immune response and vaccines like those for Covid-19, the chemistry of breathing (carbonic anhydrase), how conjugation and complexation affect the color of lobsters, and how biodegradable polymers are used to stabilize vaccines and pharmaceuticals. Content is revised to reflect the current understanding of chemical processes, and improved depictions of longstanding mechanisms. This edition builds on the ongoing pedagogical strength of the book with the inclusion of additional worked and end-of-chapter problems and an engaging set of new problems entitled "Chemical Consultant Needed". These draw from the primary chemical literature and give students experience of working with more complex, polyfunctional structures, and areas where key transformations take place.