Naming Organic Compounds (IUPAC method)
IUPAC stands for International Union of Pure and Applied Chemists.
Its task is to come up with appropriate rules for the nomenclature
of compounds as well as to create a database for all the known
compounds. This quick reference guide will provide you with the
basic step-by-step process of naming a compound; however more
complex molecules may follow further rules and exceptions. Before you deal with
complicated, this will get you through the basics!
1. Count the longest carbon chain.

1- methane

7- heptane

2- ethane

8- octane

3- propane

9- nonane

4- butane

10- decane

5- pentane

11- undecane

6- hexane

12- dodecane

2. Identify and name the groups attached to this chain (substituents)
 Methyl
 Ethyl
 Propyl
 isopropyl
 Butyl
 isobutyl
 sec-butyl
 tert-butyl
 etc
3. Number the longest chain consecutively starting at the end nearest a substituent group
4. Give each substituent its appropriate number and name.
5. Put the name together by listing the substituent groups in alphabetical order and end it
with the name of the longest chain.
 Prefixes such as di, tri, and tetra are considered when alphabetizing.
Other things to consider:
 Rings start with the prefix cyclo- (ex. 5 carbon ring is cyclopentyl). The prefix cyclo
counts in alphabetizing the name.
 Carbons with more than one substituent must be numbered that many times and use
the appropriate prefix (ex. Di, tri, tetra, etc).
o For example: 2,2-dimethyl____
 Cl- chloro, Br-bromo, I- iodo
 Alcohols (OH group) would cause the name to end in –ol. (Ex. Pentanol, ethanol, etc).
Depending on where the OH is on the longest chain it would be named accordingly (ex.
Butan-4-ol or 4-butanol)
 Double bonds would cause the longest chain to be named ending in –ene. (ex. Butene).
It would also be named and numbered like an alcohol (ex. Butan-4-ene or 4-butene).
 Triple bonds result in the suffix –yne and are named like double bonds.
 If something is on the carbon numbered 1, it does not necessarily have to be written,
but is not wrong if it is written.
Examples:
The longest chain was
not identified correctly.