Cahn-Ingold-Prelog Rules Assign a priority number to each group attached to the chiral carbon. Priority is assigned according to atomic number.The highest atomic number assigned is the highest priority #1. In case of ties,look at the next atoms along the chain. Double and triple bonds are treated like bonds to duplicate atoms. Chapter 5 10 Chapter 5 10 Cahn–Ingold–Prelog Rules • Assign a priority number to each group attached to the chiral carbon. • Priority is assigned according to atomic number. The highest atomic number assigned is the highest priority #1. • In case of ties, look at the next atoms along the chain. • Double and triple bonds are treated like bonds to duplicate atoms