R/S System of Nomenclature

The R/S system of nomenclature is the most widely used method for designating the absolute configuration of chiral centers (stereocenters) in molecules, particularly for optical isomers (enantiomers). Developed by Robert Cahn, Christopher Ingold, and Vladimir Prelog, this system follows a set of priority rules—called the Cahn-Ingold-Prelog (CIP) rules—to distinguish between two mirror-image forms (enantiomers) of…