Stereoselectivity is a term used in organic chemistry to describe the phenomenon where a reaction or process selectively produces one stereoisomer (stereoisomers are molecules that have the same molecular formula and bond connections but differ in the spatial arrangement of their atoms) over others. This selectivity can result in higher yields of the desired product and is important in the synthesis of drugs, natural products, and other complex molecules. Stereoselectivity can be influenced by a variety of factors, such as steric hindrance, electronic effects, and the nature of the reacting groups. Researchers study stereoselectivity to better understand the mechanisms behind these selective processes and to develop more efficient and effective synthetic methods.