Naming organic molecules rules (nomenclature)
We will use this molecule as an example
- Count the longest chain of carbon atoms to get the stem of the molecule name
- If there are two carbon chains of the same length , the main carbon chain will be the one with the most side chains attached.
- You include the carbon in a functional group when counting the chain length if there is one
- In this case the stem will be pent
The functional groups gives you the Prefix and/or suffix. In this case the molecule is an alcohol so will end in the suffix – ol
- Number the longest carbon chain so that the lowest number carbon has the main functional group.
- Where there is a halogen and another functional group the halogen is counted second
Pentan - 2 - ol
Use di, tri and tetra to indicate the number of identical side branches. If different side branches are present they are listed alphabetically