Book excerpt: Synthesis of Azetidines from Imines by Cycloaddition Reactions presents several methodologies for the synthesis of azetidines from imines by cycloaddition reactions. The azetidines, known as important contribution of science to humanity, are important organic compounds that have occupied a basic position in the pharmaceutical chemistry for over a hundred years because of their biological activities. They are the fundamental skeleton of several antibiotics, probiotics and alkaloids. The synthesis of azetidines is a constant challenge for medicinal chemists, hence this book comprehensively describes azetidine ring synthesis. With this book, readers will be able to quickly assess possible synthetic approaches and evaluate whether preparation of a four-membered nitrogen containing ring is reasonable. Highlights cycloaddition reactions of imines Covers the synthesis of azetidines