Naming Branched Alkanes
Branched Alkanes: an aliphatic hydrocarbon that has a carbon “branch” that substitutes a hydrogen on the
hydrocarbon chain.
Naming Branched Alkanes
1. Identify the longest carbon chain
2. Identify and name the substituted group
 Prefix plus –yl ending (methyl)
3. Number the chain so the sub. groups get the lowest number
4. If multiple groups are used, list in alphabetical order
If multiple of the same group, use the prefix with the name
Example 1:
Longest Chain?
Circle the branches
Name the branches with branches having
lowest number
Example 2:
You Try!
1.
2.
Halogenated Alkanes
Similar to naming branched alkanes, you need to include a number, indicating which carbon the halogen is
bonded to. To name the halogen, use fluoro, chloro, bromo, or iodo.
Practice:
2-chloro pentane
2 bromo, 3 fluoro heptane
2,3 dichloro pentane
Cyclo-hydrocarbons
 An organic compound consisting of carbons that are singley bonded in a ring.
 Naming: same as before, only include the prefix cyclo
Name the following branched alkanes:
Drawing Branched Alkanes
Drawing Branched Alkanes:
 Draw the longest chain first
 Place alkyl groups on the designated carbons
 Place remaining spaces with hydrogens, if structural
Draw the structural formula or skeletal formula for the following molecules. Remember the following:
 Carbons on the end of a chain are attached to three hydrogens
 Carbons in the middle of a chain are attached to two hydrogens
 Carbons that have one branch attached are also attached to one hydrogen
 Carbons that have two branches attached are not attached to any hydrogens
Examples 1:
2,3 dimethyl- heptane
Example 2:
4 methyl , 3 propyl- octane
4-ethyl-octane
3,3-dimethyl-pentane
3-ethyl-pentane
3-ethyl-2methyl-heptane
2,2,3-trimethyl-butane
3 bromo, 2 fluoro, 3 methyl heptane