Classes of compound
| Site: | Prefrontal Learning Center |
| Course: | (a) interpret, and use the nomenclature, general formulae and displayed formulae of the following classes of compound: |
| Book: | Classes of compound |
| Printed by: | Guest user |
| Date: | Thursday, 5 December 2024, 3:31 AM |
1. Count the number of carbon in chain
| meth | 1 |
| eth | 2 |
| prop | 3 |
| but | 4 |
| pent | 5 |
| hex | 6 |
| hept | 7 |
| oct | 8 |
| non | 9 |
| dec | 10 |
2. Suffix
The suffix identifies the principal functional group the molecule contains
| Classes of organic compounds | Suffix |
| Alkanes | -ane |
| Alkenes | -ene |
| Alcohols | -ol |
| Aldehydes | -al |
| Ketones | -one |
| Carboxylic acids | -oic acid |
| Esters | -oate |
| Amines | -amine |
| Amides | -amide |
2.1. Straight Chain Alkane
| Alkane | Molecular formula |
|---|---|
| Methane | CH₄ |
| Ethane | C₂H₆ |
| Propane | C₃H₈ |
| Butane | C₄H₁₀ |
| Pentane | C₅H₁₂ |
| Hexane | C₆H₁₄ |
| Heptane | C₇H₁₆ |
| Octane | C₈H₁₈ |
| Nonane | C₉H₂₀ |
| Decane | C₁₀H₂₂ |
2.2. Straight Chain Alkene
| Name | Molecular Formula |
| Ethene | C₂H₄ |
| Propene | C₃H₆ |
| Butene | C₄H₈ |
| Pentene | C₅H₁₀ |
| Hexene | C₆H₁₂ |
| Heptene | C₇H₁₄ |
| Octene | C₈H₁₆ |
| Nonene | C₉H₁₈ |
| Decene | C₁₀H₂₀ |
3. Prefix
Prefix gives the locations of the other functional groups (other than
the principal functional group) on the stem.
o Prefix is used to denote any substituent in an organic compound.
o Placed in alphabetical order if there is more than 1 prefix.
o For multiple prefix, use di, tri, etc
| Substituent Group | Name as Prefix |
| \(-CH_3\) | Methyl- |
| \(-C_2H_5\) | Ethyl- |
| \(-C_3H_7\) | Propyl- |
| \(-C_4H_9\) | Butyl- |
| Substituent Group | Name as Prefix |
| \(-F\) | Fluoro- |
| \(-Cl\) | Chloro- |
| \(-Br\) | Bromo- |
| \(-I\) | Iodo- |
| Substituent Group | Name as Prefix |
| \(-OH\) | Hydroxy- |
| \(-NO_2\) | Nitro- |
| \(-NH_2\) | Amino- |
| \(-C_6H_5\) | Phenyl- |
| \(-CN\) | Cyano- |
4. Steps to Naming Organic Compounds
(1) Identify the stem, which is the longest chain of carbon atoms.
5. Steps to Naming Organic Compounds
The parent chain is numbered so that the lowest possible number is given for the substituents. Circle the substituents
Substituent alkyl groups are at positions 2 & 4 (instead of 4 & 6).
6. Steps to naming
Name each substituent and indicate its position by the number of the carbon atom to which itis attached.
IUPAC name: 4-ethyl-2-methylheptane
7. Steps to Naming
If the carbon chain is substituted by the same group more than once, the number of identical groups is indicated by the prefixes: di, tri, tetra....
8. Steps to Naming
If there are two or more substituents, they should be named in alphabetical order (excluding the prefixes di, tri, tetra, etc.)