1
3-ethylhexane
2
1-bromo-3-methylbutane
3-ethylhexane
2
1-bromo-3-methylbutane
1 the longest chain has six carbon atoms.
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The name is based on the longest chain containing the functional group.
2 the longest chain with the functional group has four carbon atoms.
Any atom or group of atoms replacing H at a carbon is called a substituent.
- Substituents on the longest chain are included in the name as prefixes. Common substituents are:
bromo Br– methyl CH3– chloro Cl– ethyl CH3CH2–
Saturated hydrocarbon substituents have the same name as the parent alkane with the -ane substituted by -yl. Compound 1 has an ethyl substituent. Compound 2 has a methyl and a bromo substituent
3.
2,2-dimethylpentane
4
2,3-dimethylbutane - The functional group in the compound determines the numbering of the chain. The number is referred to as the locator in the name.
For haloalkanes, the carbon with the halogen has the lowest possible number (2).
For alkanes the carbon with the alkyl substituent has the lowest possible number.
- The prefix di- is used if a compound has two of the same substituent.
The locators, separated by a comma and followed by a dash, precede the name. See 3 and 4.