Monocyclic Compounds Parent names are given for saturated monocyclic hydrocarbons based on n, the total number of atoms in the ring. n 3 Cyclopropane 4 Cyclobutane 5 Cyclopentane 6 Cyclohexane 7 Cycloheptane 8 Cyclooctane 9 Cyclononane 10 Cyclodecane etc. ...	Consider the ring system that contains the principal functional group. The suffix (-ane) is modified to denote principal functional group contained within the main chain. The modifications are made: 1) according to the principal functional group: -ane becomes -an-(suffix) and 2) in accordance with unsaturation double bonds: -ane becomes -ene, -adiene, -atriene, etc. triple bonds: -ane becomes -yne, -adiyne, -atriyne, etc. locants are used to identify the position(s) of unsaturation
Bicyclic Polycyclic and Spiro Compounds The parent system is described as being made of bridges and bridgeheads. A bridge is a bond, an atom, or a chain of atoms connecting two different atoms that are already part of a cycle. The bridgeheads are the two atoms in the original cycle that are connected by the bridge. The number of rings and total number of carbon atoms in the parent system determines the name. The numbers of atoms in the bridges are listed in descending order as shown.
Heterocycle Naming Heterocycles have the most memorization-intensive naming system. The name of a heterocycle is modified to contain a prefix (Table 1) for the heteroatom in the ring (along with multiplicative prefixes and locants if necessary). The suffix (Table 2) is determined by the ring size (and unsaturation). Table 1: heteroatom prefix N az(a)- O ox(a)- S thi(a)- Table 2: Ring size Unsaturated Saturated 3 irene irane 4 ete etane 5 ole olane 6 (O,S) ine ane 6 (N) ine inane 7 epine epane 8 ocine ocane 9 onine onane 10 ecine ecane
Many trivial names are still used. A list of the most common trivial names is available. Return to the flow chart