The general form of the name of a organic compound is:$^1$
prefix + stem name + suffix
In order to name organic compounds, there are 3 rules that you have to remember.$^1$
Identify the number of carbon atoms in a molecule and name the carbon chain.
This means that you have count the number of carbon atoms(the carbon number) and from it find the stem name. Bellow is a table that does just that.$^1$
| Carbon Num | Stem name |
|---|---|
| 1 | meth |
| 2 | eth |
| 3 | prop |
| 4 | but |
| 5 | pent |
| 6 | hex |
| 7 | hept |
| 8 | oct |
| 9 | non |
| 10 | dec |
Identify the functional group, sometimes abbreviated as f.g, and add the name of the functional group as the suffix to the name.
The functional group is the active part of the molecule, which brings the difference in physical and chemical properties of the compounds.$^1$
| Class name | Functional Group | Functional Group Name | General Formula | Example |
|---|---|---|---|---|
| Alkane | link to picture | -ane | $\text{C}n\text{H}{2n+2}$ | $\text{C}7\text{H}{16}$ |
| Alkene | link to picture | -ene | $\text{C}n\text{H}{2n}$ | $\text{C}7\text{H}{14}$ |
| Alkyne | link to picture | -yne | $\text{C}n\text{H}{2n-2}$ | $\text{C}7\text{H}{12}$ |
| Alcohol | link to picture | -ol | $\text{C}n\text{H}{2n+2}\text{O}$ or $\text{C}n\text{H}{2n+1}\text{OH}$ | $\text{C}7\text{H}{15}\text{OH}$ |
| Carboxylic Acid | link to picture | -oic acid | $\text{C}n\text{H}{2n}\text{O}_2$ | $\text{C}7\text{H}{14}\text{O}_2$ |
| Ester(From reacted alcohol and carboxylic acid) | link to picture | -oate | $\text{C}n\text{H}{2n}\text{O}_2$ | This is covered more in depth in the Ester section. |
Identify the substituent, if any, and name the substituent as a prefix to the stem name.
Substituents replace Hydrogen in the organic compound.$^1$
For a molecule like chloropropane, the chlorine atom can be on different carbon atoms. Each iteration of it is a different compound with different properties. So how do you name it? You take the least preferable count.$^1$
The count can either be 1 or 3. Because 1 is less than 3, you choose 1. Hence the name is 1-chloropropane. However when the count is 1, you can drop it.
The count can only be 2. Hence the name is 2-chloropropane.
This molecule is the same as the first one. The name is also 1-chloropropane or just chloropropane.
For a case like chlorobutane where the chlorine atom is either on the second or the third carbon, you take the least count. So it would be 2-chlorobutane.$^1$
