 Naming Branched-Chain Alkanes

CH3-CH2- CH2-CH -CH -CH -CH3
CH2 CH3CH3
CH3
1. An atom or group of atoms can take the place of a
hydrogen, this is called a substituent.
ex) halogens, groups of atoms including carbon, O,S,N,P
2. A hydrocarbon substituent is called an alkyl group. An alkyl
group can be several carbons long.
a) the ending of the hydrocarbon substituent is -yl
ex) methane --- methyl
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CH3-CH2- CH2-CH -CH -CH -CH3
CH2 CH3CH3
CH3
IUPAC rules for naming - name the parts and then put them
all together into one name
1. Find the longest continuous chain of carbons in the
molecule.
Heptane
2. Name the substituent groups and then number them so
that they will have the smallest number.
2-methyl, 3-methyl, 4-ethyl
3.Use a prefix for a group that occurs more than once.
2,3-dimethyl, 4-ethyl
4. Then list in alphabetical order ignoring prefixes.

4-ethyl-2,3-dimethyl
CH3-CH2- CH2-CH -CH -CH -CH3
CH2CH3 CH3
CH3
 Proper punctuation:
Commas separate numbers

Hyphens separate numbers and words
 Name is written as one word.
4-ethyl-2,3-dimethylheptane
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 Give it a try. Name these:
 A) CH3-CH-CH2-CH3
CH2
CH3
CH3
B) CH3-CH2-C-CH3
CH2
CH2
CH3
A) 3-methylpentane
B) 3,3-dimethylhexane
A couple of more your turns:
Name:
C
C
C-C-C-C-C
C
C
Draw: 3-ethyl-2,4-dimethyloctane
Answers: 2,2,4,4-tetramethylpentane
C-C-C-C-C-C-C-C
CCC
C
What do you do if there is a double or triple
bond?
The double or triple bond takes
precedence in the number. It
automatically gets the lowest number
and determines carbon number 1.
Name the following:
 C
C-C-C-C-C-C=C-C
 C
7,7-dimethyl-2-octene