1. Organic Compounds (Part 2)
IUPAC Nomenclature of
Organic Compounds
(Part 2)

2. I. Naming Alkenes and Alkynes (Unsaturated Compounds)
Alkanes contain single bonds only -ANE ending
CnH2n (saturated)
Alkenes contain a double bond ENE ending
CnH2n (unsaturated)
Alkynes contain a triple bond between YNE ending
CnH2n (unsaturated)

3. Naming Alkenes & Alkynes
Name & position of branching groups
(if any) +
Change the ending of the parent name to
- ene or -yne
Indicate where double or triple bond is located
Parent Name = longest continuous chain of carbon atoms
Use Greek prefixes to indicate the presence of multiple identical branching groups.

4. C 2 3 4 1 What is the parent name? Butene (double bond present)
Must number parent chain so the carbon atoms containing the double bond have the lowest number. Use the lowest number to indicate where the double bond starts.
What position is the double bond located ?
1 position
Correct name is : 1-butene
Note: Carbon atoms can only have four bonds

5. CH3 CH CH CH CH CH3 CH3 CH3 Correct name is : 2,5-dimethyl-3-hexene 26 1 4 5
CH3 CH CH CH CH
CH3 4 1 2 3 6 5
CH3
CH3
What is the parent name?
hexene (double bond present)
What position is the double bond located ?
3 position
Location and number of groups:
2,5-dimethyl
Correct name is : 2,5-dimethyl-3-hexene
Note: Always number so the double bond gets the lowest number

6.   (CH3)2C=CHCH2C(CH3)3

7.   (CH3)2C=CHCH2C(CH3)3
2,5,5 – trimethyl-2-hexene

8. (CH3CH2CH2)2C=CH2

9. (CH3CH2CH2)2C=CH2
2-propyl-1-pentene

10. Hydrocarbons can also contain other atoms, such as halogens (F, Cl, Br, I). Halogen atoms are treated like branching alkyl groups.
Halogen
Group Name F
fluoro C
chloro Br
bromo I
iodo

11. 2-heptyne (triple bond)1 2 3 4 5 6 7
Longest chain containing triple bond?
2-heptyne (triple bond)
Location and number of groups?
4-methyl
5-ethyl
6-chloro
Name: 6-chloro-5-ethyl-4-methyl-2-heptyne

13. 6-chloro-3,3-dimethyl-4-octyne
4-bromo-5-methyl-2-hexyne
6-chloro-3,3-dimethyl-4-octyne