🥼organic chemistry review

Cahn–Ingold–Prelog sequence rules

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

The Cahn-Ingold-Prelog (CIP) sequence rules are a set of guidelines used to systematically name the spatial arrangement of atoms around a stereocenter, helping to determine the configuration of molecules in organic chemistry. These rules prioritize atoms or groups attached to a chiral center based on atomic number, isotopic mass, and connectivity, facilitating the assignment of R (rectus) or S (sinister) configurations.