1. Naming Organic Compounds
L. Scheffler
Lincoln High School
IB Chemistry 3-4. 1

2. Naming Organic Compounds
Originally compounds were named based on their source or use
Many organic compounds were given common names which are still in use
However many ambiguities resulted
With the large number of organic compounds, a method for systematically naming them is very important 2

3. IUPAC Names
The International Union of Pure and Applied Chemists (IUPAC) developed a system for naming organic compounds.
This system eliminated many of the ambiguities that plagued earlier naming systems
Common names for many substances are still widely used 3

4. Naming Hydrocarbons using the IUPAC System
A series of prefixes are used to designate the number of carbon atoms in a carbon chain
meth
1 C
hex
6 C
eth
2 C
hept
7 C
prop
3 C
oct
8 C
but
4 C
non
9 C
pent
5 C
dec
10 C 4

5. Naming Alkanes
For straight chain hydrocarbons. The prefix indicates the number of carbon atoms.
The suffix ane is added to designate that the compound is an alkane 5

6. Naming Alkanes with branched chains
For branched chain hydrocarbons, identify the longest consecutive (straight) chain first. Then name the side chains or branches.
The name of the branches end in “yl” and go before the name of the straight chain
-methylpropane
methyl butane
dimethyl propane 6

7. Alkenes Alkenes have one (or more) carbon to carbon double bonds
When there are 4 or more carbon atoms in a chain, the location of the double bond is indicated by a number.
Numbering the location of the double bond(s) takes precedence over the location of side chains
1 butene butene methylpropene 7

8. Naming Compounds With Functional Groups
Various functional groups have unique suffixes that designate the functional group.
The functional group takes precedence in numbering the carbon chain.
Branches to the carbon chain are named in the usual manner.
alcohols
“ol”
Amides
“amide”
Aldehydes
“al”
Amines
“amine” or amino as a prefix
Ketones
“one”
Ethers
Ethoxy as prefix
Acids
“oic”
halohydrocarbons
Fluoro, bromo, chloro or iodo
Esters
“oate” 8

9. Alcohols
Suffix = “ol”
1- Propanol
2- Propanol
2-methyl-2-propanol 9

10. Aldehydes and Alkanals
Suffix = “al”
Propanal
Note that the aldeyhde group is always on an end carbon or carbon 1 10

11. Ketones or Alkanones Suffix = “one” Propanone (also known as acetone)
Butanone
(also known as methyl ethyl ketone)
2-Pentanone
(note the number is necessary
Because the C=O could be on carbon
2 or carbon 3) 11

12. Carboxylic Acids Suffix = “oic” Butanoic acid
Note that the acid group (called a “carboxyl”) is always on an end carbon or carbon 1 12

13. Esters Esters Suffix = “oate” Ethyl butanoate Butyl ethanoate
There are two branches. The branch with the carbonyl gets the suffix 13

14. Amides Suffix = “amide” butanamide
Note that the amide group is always on an end carbon or carbon 1 14

15. Amines Suffix = “amine” Or prefix = “amino”
Propylamine or 1-aminopropane
2-propylamine or 2-aminopropane
2-methyl-2-propylamine or
2-methyl -2- aminopropane 15

16. Halohydrocarbons 1-bromopropane
2 chlorobutane
1,2 diiodoethane
Cis 1,2difluroethene
Trans 1,2 difluoroethene
1,1,2 trifluorothene
prefixes = “fluoro, chloro, bromo, iodo” 16

17. Ethers Suffix = “oxy”on first branch Ethoxyethane (diethylether)
Ethoxybutane
(ethylbutyl ether) 17

18. Aromatic Compounds With Functional Groups
Benzoic acid
2 hydroxybenzoic acid
3 bromobenzoic acid 18

19. Nitriles
Nitriles have a cyanide group. The name is based on the longest carbon chain that includes the carbon atom in the nitrile group. 19

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