Why is stereochemistry important in organic synthesis?

Stereochemistry plays a crucial role in organic synthesis because it influences the reactivity and function of organic compounds significantly. Different stereoisomers—compounds that have the same molecular formula and the same connectivity of atoms but differ in the arrangement of atoms in space—can exhibit vastly different chemical behaviors.

For example, the two enantiomers of a chiral molecule may interact differently with biological systems, leading to variations in pharmaceutical efficacy and safety. One enantiomer may be active and produce a desired therapeutic effect, while the other may be inactive or even harmful. This specificity is paramount in drug development, as the wrong stereoisomer could lead to ineffective treatments or serious side effects.

Additionally, the stereochemistry of reactants can dictate the pathways and rates of chemical reactions, influencing product distributions. In synthesis, controlling stereochemistry is essential to ensure the correct 3D structure of the desired product is formed, which is often vital for its intended use.