Naming of organic compounds
- rarely tested as a stand-alone qns but as a prerequisite for other qns-
The name of an organic compound has three parts:
| PREFIX | STEM | SUFFIX |
|
STEM: No. of C atoms in the longest continuous chain. |
| # of C atoms | stem name |
| 1 | meth- |
| 2 | eth- |
| 3 | prop- |
| 4 | but- |
| 5 | pent- |
| 6 | hex- |
| 7 | hept- |
| 8 | oct- |
| 9 | non- |
| 10 | dec- |
-
Cyclic compounds are named with a 'cyclo' in front of the stem e.g. cyclopentane
|
SUFFIX: (1) functional group present and (2) position |
| functional group | suffix name |
| carboxylic acids | -oic acid |
| esters | -oate |
| acyl chlorides | -anoyl chloride |
| amides | -amide |
| nitriles | -nitrile |
| aldehydes | -al |
| ketones | -one |
| alcohols | -ol |
| amines | -amine |
| alkenes | -ene |
| alkynes | -yne |
| alkanes | -ane |
A number is placed in front of the suffix to indicate the position of the functional group e.g. butan-2-ol
|
PREFIX: (1) substituents present and (2) # and position |
Alkyl substituents
| # of C atoms | substituent | suffix name |
| 1 |
-CH3 |
methyl |
| 2 |
-C2H5 |
ethyl |
| 3 |
-C3H7 |
propyl |
| 4 |
-C4H9 |
butyl |
| 5 |
-C5H11 |
pentyl |
No-alkyl substituents
| substituent | prefix name |
| -F | fluoro |
| -Cl | chloro |
| -Br | bromo |
| -I | iodo |
| -OH | hydroxy |
| -C=O | oxo |
| -NO2 | nitro |
| -C≡N | cyano |
A number is placed in front of the prefix to indicate the position of the substituent e.g. 2-methylbutane
If there is more than 1 of the same substituent, the following term is added in front of the prefixe.g. 2,3-dimethylbutane
| # of same substituent | prefix |
| 2 | di |
| 3 | tri |
| 4 | tetra |
Hyphens are used to separate numbers and words
Commas are used to separate two numbers
Different substituents appear in the IUPAC name in alphabetical order e.g. 3-chloro-2-hydroxybutanoic acid instead of 2-hydroxy-3-chlorobutanoic acid
