Textbook in PDF format Bioactive Four-Membered Heterocycles provides detailed information on the green synthesis of the structurally diverse pharmaceutically active four-membered heterocycles. It covers both synthesis and biological aspects and highlights the role of four-membered heterocycles in drugs and drug designing. It also includes naturally occurring bioactive four-membered heterocycles. State-of-the-art guide on 4-membered heterocycles. Indispensable to medicinal chemists. Some commercially available β-lactam antibiotics Chemistry and biology of β-lactams as anticancer agents Role of four-membered heterocycles in drugs and drug designing Synthesis of pyrrole-substituted β-lactams by diverse catalytic methods Applications of greener methodologies in the synthesis of bioactive oxetanes Four-membered heterocycles via photochemical means Applications of Paternò-Büchi reactions for the construction of four-membered heterocycles Synthesis of four-membered heterocycles by microwave irradiation Synthesis of four-membered heterocycles under electrolysis Organocatalyzed synthesis of four-membered heterocycles Applications of four-membered heterocycles to construct higher-membered heterocycles Industrial applications of four-membered heterocycles