Cyclohydrocarbons: Nomenclature

Substituted cycloalkanes are named in a manner similar to the openchain, or aliphatic, alkanes. The following rules summarize the International Union of Pure and Applied Chemistry (IUPAC) nomenclature for substituted cycloalkanes.

  1. Determine the number of carbon atoms in the ring and in the largest substituent. If the ring has more carbons than the substituent, the compound is an alkyl‐substituted cycloalkane. If the substituent possesses more carbons than the ring, the compound is a cycloalkyl alkane.

  2. If an alkyl‐substituted cycloalkane has more than one substituent, the ring is numbered so the substituents have the lowest sum of numbers.

  3. If the molecule possesses two or more different substituent groups, the number one position is determined by alphabetical priority.