Naming Functional Groups
Functional Groups that have a prefix
1. Branched alkanes
a. See hydrocarbons notes
2. Haloalkanes
a. Name the longest carbon chain
b. Give a prefix for the halogen:
i. Flouro
ii. Chloro
iii. Bromo
iv. Iodo
c. Number the location of the halogen so that it has lowest # possible
d. If more than one halogen, use di/tri prefix
Cl
Cl
CH 3
Cl
H
H
CH 3
Br
H3C
CH 3
CH 3
chloroethane
2-bromo-2-chlorobutane
Cl
2,3-dichlorobutane
Functional Groups that have a different ending than -ane
3. Alkenes/Alkynes
a. Find longest carbon chain
b. Add –ene for a double bond ending or –yne for a triple bond
c. Number the location of the double bonds so it has lowest # possible
propene
1-butyne
2-butene
4. Alcohols
a. Name longest chain
b. Use ending –anol
c. Number carbons to figure out what carbon the –OH group is on
d. Number can go at the front or right before ending. The latter is often used when there is
more than one functional group on a molecule
OH
OH
propan-1-ol
or: 1-propanol
propan-2-ol
or: 2-propanol
OH
pentan-3-ol
or: 3-pentanol
i. Classification
1. primary 1 - attached to 1 R group (at the end of a carbon chain)
2. secondary 2 - attached to 2 R groups (at a branch of a carbon chain)
3. tertiary 3 - attached to 3 R groups
R
R
H
R C O
H
H
H
C
O
R
primary
secondary
H
R
C
O
R
H
tertiary
5. Ethers
a. Naming (easy)
i. Identify the carbon chains on either side of the oxygen
ii. Name in alphabetical order or use di/tri prefix
iii. Put “ether” on the end
CH 3
O
H3 C
CH 3
H3 C
dimethyl ether
O
ethyl methyl ether
b. Naming (when ether is a substituent)
i. Name longest carbon chain
ii. Name other carbon chain attached to O and add –oxy ending
iii. Number comes from carbon that O is attached to on longest carbon chain
O
CH 3
H3C
CH 3
2-methoxypropane
6. Amines
a. Name longest carbon chain
b. Add –anamine ending
c. If more than one chain attached to N, use branching rules as with alkanes but use N
instead of number of carbon to show alkyl group is attached to nitrogen.
CH3
NH2
H3C
methanamine
N
CH3
H3C
NH
N-methylethanamine
H3C
CH3
N-ethyl-N-methylpropan-1-amine
7. Aldehydes/Ketones
a. Name longest chain
b. If carbonyl (C=O) is
i. on the end: Use ending –anal
1. no number needed unless higher priority functional group is on molecule
ii. in the middle: Use ending -anone
1. Number carbons to figure out what carbon the C=O group is on
2. Number can go at the front or right before ending. The latter is often used
when there is more than one functional group on a molecule
O
O
H3 C
CH 3
H
propanal
ethanal
2-propanone
Aldehyde
Ketone
8. Carboxylic Acids
a. Name longest chain
b. Use ending –anoic acid
O
O
H3 C
OH
ethanoic acid
OH
propanoic acid
9. Esters
a. Count number of carbons in chain attached to carbonyl (C=O) including carbonyl’s
carbon
b. Add –anoate ending
c. Name alkyl group attached to O and add as prefix
O
O
H3C
H3C
O
O
CH 3
ethyl propaonate
methylethanoate
10. Amides
a. Name longest carbon chain
b. Add –anamide ending
c. If Nitrogen has substituents, use “N-(substituent)” name and add as prefix
O
O
H3C
H3C
NH2
ethanamide
NH
N-ethylpropanamide
CH 3