Naming Alkanes

1. Find the longest continuous chain of carbons. • This is the parent chain.

Ethyl branch attached to a hexane chain:

C - C - C - C

C

C

C - C -

1

2

3 4 5 6

6

5

4 3 2 1

2. Branches - Number the carbons of the parent chain from the end that gives the lowest number to the first branch:

3. Name each alkyl group including the number of the parent carbon it is attached to showing position.

4. Names are all ONE word. • Hyphens used to separate numbers from words.

3-ethylhexane

C - C - C - C

C

C

C - C -

1

2

3 4 5 6

Draw the structural formula for 2-methylhexane.

1 2 3 4 5 6

CH3CH(CH3)CH2CH(CH3)CH3

2,4-dimethylpentane

1 2 3 4 5

5. Multiple alkyl groups require prefixes (di, tri) and parent numbers for each.

• The alkyls are named in alphabetical order.• Commas are used to separate numbers.

(5-ethyl-2,4-dimethyloctane)

C - C - C - C

C

C

C - C -

6

5

4 3 2 1

C

4-ethyl-2-methylhexane

5-ethyl-2,4-dimethyloctane

C - C - C - C - C - C

C

C

C - C - 3

4

5 6

C

7 81 2

C

3,3,5trimethyloctane

3 4

5

6 7 8

12

3-ethyl-2,7-dimethyl-4-propyloctane

CH3CH2CH2CH(C2H5)CH2C(CH3)2CH3

4-ethyl-2,2-dimethylheptane

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• Organic chemistry is the study of carbon compounds.

• Carbon will usually make 4 covalent bonds.

• Alkanes contain only single carbon - carbon bonds.

• The general formula of an alkane is CnH2n+2