ORGANIC CHEMISTRY
A Study Guide for alcohols, ethers, aldehydes, ketones,
carboxylic acids, esters, amines and polymers
ALCOHOLS
THE NAMING OF ALCOHOLS
The iupac naming of alcohols begins by choosing the longest hydrocarbon chain containing the OH functional
group. 1) Locate the OH group using the lowest possible numbering and 2) The ending “e” is removed form the
base name replaced by “ol”. (The common naming system involves using the base name with a “yl” ending.
Example methyl alcohol.
Eg.
CH3 – CH2 – CH2 – OH
1- propanol
CH3 – CH – CH2 -CH3
|
OH
2 – butanol
EXERCISE
1.
Name and classify each of the following (using the IUPAC system):
a) CH3 – CH2 –CH –CH2 –CH – CH3
l
l
OH
CH3
2o 5-methyl-3-hexanol
b)
1o
HO – CH2 – CH – CH3
l
CH3
2-methyl-1-propanol
OH
|
2-methyl-2-propanol
c) H3C – C – CH3
|
3o
CH3
2.
Draw the condensed structural formula for:
a) 2 – pentanol
c) 2 – methyl – 2- propanol
CH3-CH2-CH2-CH-CH3
|
OH
CH3 OH
\/
CH3-C-CH3
b) 4,4 – dimethyl -1- hexanol
HO
Questions
1.
Write the reaction of how you would prepare 2-pentanol. Could you produce this in 100% yield?
a. Add 1-pentene to water (Markovnikov Addition) and 2-pentanol will be prepared in a 100%
yield
b.
If you tried 2-pentene you would only get a 50/50 mixture of 2-pentanol and 3-pentanol
2.
What functional group would be the result of the addition of KMnO4 to:
a) 2-butanol
ketone
b) 3-methyl-3-hexanol
n.r. (alcohol)
c) ethanol
aldehyde or carboxylic acid
3.
Write the balanced chemical equation for the combustion of 1-propanol.
2 C3H7OH + 9 O2 → 6 CO2 + 8 H2O
If methanol was oxidized to methanal (aldehyde) and KMnO4 was reduced to MnO2; give the balanced
redox reaction if it took place in an acidic solution.
4.
CH3OH → CH2O + 2H+ + 2e- (X3)
3e- + 4H+ + MnO41- → MnO2 + 2H2O
(X2)
2H+ + 2MnO41- + 3CH3OH → 2 MnO2 + 4H2O + 3CH2O
ETHERS
NAMING OF ETHERS
1)
2)
Choose the longest alkyl group as the parent alkane.
Treat the second alkyl group as the branch alkyl group. This is named by replacing the “yl” with “oxy”.
The alkoxy group that is adding on to the main chain should be located onto the main chain with an
appropriate number.
Eg. CH3 – O – CH2 – CH3
methoxyethane
CH3 – CH2 –O – CH – CH3
\
CH3
2- ethoxypropane
EXERCISE
1.
Name the following ethers.
a) CH3 – CH2 – CH2 – CH2 – O – CH3
1-methoxybutane
b) CH3CH2CH2CH2 – O – CHCH2CH2CHCH2CH3
|
|
CH3
CH3
2-butoxy-5-methylheptane
c)
2.
CH3 – CH – O – CH2 – CH – CH2 – CH3
|
|
CH3
CH3
1-isopropoxy-2-methylbutane
Draw the following ethers.
a) 1-methoxy propane
b) 3 – ethoxy-4-methylheptane
CH3 – O – CH2 – CH2 – CH3
CH3 – CH2 – O
CH3
|
|
CH3 – CH2 – CH – CH – CH2 – CH2 – CH3
c) 2 – methoxy – 2- methylpropane
CH3 – O
CH3
\ /
CH3 – C – CH3
ALDEHYDES AND KETONES
THE NAMING OF ALDEHYDES AND KETONES
The naming of aldehydes and ketones begins by choosing the longest chain containing the carbonyl group to
obtain the base name. The ending “e” is removed from the base name and replaced by the suffix “al” in the
case of aldehydes and “one” in the case of ketones. Since the carbonyl group of an aldehyde is always at one
end of the main chain, its position does not require a number. However, for ketones, we use a number to show
the location of the carbonyl group (starting the count from the end closest to the carbonyl group).
Examples:
CH3
O
|
||
O
CH3
||
|
CH3-CH-CH2-C-H
CH3 – C – CH2 – CH – CH3
3-methylbutanal
4-methyl-2-pentanone
EXERCISE:
1. Name the following using IUPAC system:
CH3
O
|
||
a) CH3 – CH – CH2 – CH2 – C – CH3
CH3 O
| ||
CH3 – C – C -H
b)
|
CH3
2. Draw the structural formula for:
a) 3-pentanone
b) butanal
CH3-CH2-CO-CH2-CH3
c) 2-methylpentanal
CH3-CH2-CH2-CHO
d) 2,4-dimethyl-3-hexanone
O
||
||
O
Questions
1. Write an equation for each of the following reactions:
a) Balance the reaction between methanal and acidified Cr2O72- ions.
Hint: This reaction is a redox reaction. Combine the following two half reactions to obtain a balanced
equation.
The oxidation half-reaction:
H2O + HCHO
The reduction half-reaction:
6e- + 14 H+ +
HCOOH + 2H+ + 2 e-

Cr2O72-
—>
(X3)
2 Cr3+ + 7 H2O
8H+ + 3HCHO + Cr2O72-  3HCOOH + 4H2O + 2 Cr3+
b)The reaction between propanal and hydrogen gas over platinum as a catalyst.
CH3-CH2-CHO + H2,Pt → CH3-CH2-OH
1-propanol
c) The oxidation of 2-methylpropanal with acidified potassium dichromate ions.
CH3-CH-CHO + [O] → CH3-CH-COOH
|
|
CH3
CH3
2-methylpropanoic acid
2. Which alcohol would you oxidize to prepare a) pentanal and b) 3-pentanone.
Write a balanced half reaction for each reaction.
a)
CH3-CH2-CH2-CH2-CH2-OH
1-pentanol
b)
CH3-CH2-CH-CH2-CH3
3-pentanol
|
CH3
CARBOXYLIC ACIDS
THE NAMING OF CARBOXYLIC ACIDS
The IUPAC names of CARBOXYLIC ACIDS are obtained by selecting the longest carbon chain containing the
CARBOXYL group and replace the ending of the alkane name with the ending “oic acid”. If an alkyl group is
present, the numbering starts from the carbon of the carboxyl group.
EXAMPLE:
O
||
CH3 – CH2 – CH – CH2 – CH2 – C – OH
4-ethylhexanoic acid
|
CH2 - CH3
EXERCISE:
1. Name the following carboxylic acids using IUPAC system:
a)
CH3 CH3
O
\ /
||
b)
CH3 CH3
|
|
CH3 – CH2 – C – CH2 – C – OH
CH3 – CH – CH - COOH
3,3-dimethylpentanoic acid
2,3-dimethylbutanoic
2. Draw the condensed formula for:
a) Heptanoic acid
b) 4-methylhexanoic acid
CH3-CH2-CH2-CH2-CH2-CH2-COOH
CH3-CH2-CH-CH2-CH2-COOH
|
CH3
QUESTIONS
1.
What ions form when propanoic acid reacts with water?
CH3-CH2-COOH + H2O → CH3-CH2-COO- + H3O+
2.
Why does butanoic acid have a higher BP than 3-pentanone?
CH3-CH2-CH2-COOH and CH3-CH2-CO-CH2-CH3 have roughly the same London forces and both contain
a carbonyl group (C=O) so they both have a polar area. However, they differ because butanoic acid has an
–OH bond so it has hydrogen bonding as an IMF.
3.
If ethanoic acid is reduced with H2, what two possible products can form? (name and draw their
condensed structural formulas)
CH3COOH + H2, Pt →
4.
CH3CHO + H2, Pt →
CH3CH2OH
Ethanal
ethanoic acid
What alcohol needs to be oxidized to prepare 3-methylpentanoic acid?
CH3-CH2-CH-CH2-CH2-OH
3-methyl-1-pentanol
|
CH3
Oxidation ADD A STRONG OXIDIZING AGENT TO THE FOLLOWING ORGANIC COMPOUNDS. NAME THE
PRODUCTS.
a) ethanol
CH3-CH2-OH + [O] →
b) 3 - methyl-3-pentanol
c) 2 – methylpropanal
CH3-CHO + [O] →
ethanal
CH3-COOH
ethanoic acid
CH3-CH2 – C – CH2 – CH3 + [O] → nr
/ \
CH3 OH
CH3 – CH – CHO + [O] → CH3 – CH – COOH
|
|
CH3
CH3
d) 3,3 dimethyl -2-pentanol
2-methylpropanoic acid
O
||
CH3-CH2 – C – CH – CH3 + [O] → CH3-CH2 – C – C – CH3
/ \
\
/ \
CH3 CH3 OH
CH3 CH3
3,3 – dimethyl -2- pentanone
REDUCTION REACTIONS
DRAW THE FOLLOWING COMPOUNDS AND SHOW THE REDUCTION PRODUCT. Name all the new
compounds.
a) 3-pentanone
+ H2, Pt →
3-pentanol
O
b) 3,4 dimethylpentanal
OH
CH3 – CH – CH – CH2-CHO + H2, Pt →
| |
CH3 CH3
CH3 – CH – CH – CH2-CH2OH
|
CH3
c) 2,4,4 trimethyl-2–pentene
+ H2, Pt →
2,2,4-trimethylpentane
d) methanal
HCHO + H2, Pt → CH3OH
methanol
ESTERS
NAMING OF ESTERS
In naming esters, we obtain the first part of the name from the name of the alkyl group attached to the
oxygen; the second part is obtained by changing the “-ic acid” ending of the acid to -ate.
EXAMPLES
O
O
||
||
CH3 – C – O – CH3
CH3 – CH2 – CH2 – C – O – CH – CH3
methyl ethanoate
2 – propylbutanoate
|
CH3
QUESTIONS
I. Give the IUPAC name for:
a)
O
||
H—C-O-CH2 – CH2 – CH3
Propyl methanoate
b)
O
CH2 – CH3
||
|
CH3 – CH2 - C – O – CH – CH2 –CH3
3-pentyl propanoate
2. There are two esters with the formula C3H6O2
a) Draw their condensed formulas.
CH3-COO-CH3
AND
HCOO-CH2-CH3
b) Give their IUPAC names
methyl ethanoate and ethyl methanoate
c) Identify the alcohol and the carboxylic acid used in the preparation of each ester.
Methanol and ethanoic acid
ethanol and methanoic acid
d) Name and draw the isomeric carboxylic acid.
CH3-CH2-COOH
propanoic acid
e) Compare the BP of either ester to (d).
Propanoic acid has a higher BP because it has hydrogen bonding – either ester has only a dipole force. London
forces are roughly equal.
3. Write the esterification reaction between:
a) ethanoic acid and ethanol.
CH3-COOH + HOCH2-CH3 → CH3 – COO – CH2-CH3
b) methanoic acid and 1-butanol.
HCOOH + HOCH2-CH2-CH2-CH3 → HCOO – CH2-CH2-CH2-CH3
c) propanoic acid and 2-methyl-2-propanol.
CH3-CH2-COOH + HOC - C -CH3 → CH3-CH2–COO – C -CH3
/ \
/ \
CH3 CH3
CH3 CH3
4. Write a balanced equation to show how each ester below is prepared
a) CH3 – CH2 – COO – CH2 – CH2 – CH2 – CH2 - CH2 – CH3
CH3-CH2-COOH + HOCH2-CH2-CH2-CH2-CH2-CH3 →
b) H – COO – CH2 – CH2 –CH2 – CH3
HCOOH + HO-CH2-CH2-CH2-CH3 →
AMINES
THE NAMING OF AMINES:
The IUPAC names of amines are formed by adding the prefix amino- to the corresponding alkane name of the
amine. As usual, numbers are used to indicate the carbon to which the amine substituent is attached. The
functional group takes priority over the alkyl group. (In this course we will only have to name primary amines).
CH3-NH2
aminomethane
CH3 – CH – CH2 – CH – CH2 – CH3
|
|
CH3
NH2
3-amino-5-methylhexane
QUESTIONS
1. Name and classify the following amines.
a) NH2 – CH2 – CH2 – CH – CH3
b)
|
NH2
NH2
NH2
1,3 – diaminopropane
1,4-diamino-2-methyl
c) NH2 – CH2 – CH2 – CH2 – CH – CH – CH3
|
1-amino – 4,5-dimethylhexane
|
CH3 CH3
2. Draw the structural formulas of four amines that have the molecular formula C3H9N (two primary, one
secondary, and one tertiary amine). Classify the amines and name the primary amines among them.
1) CH3-CH2-CH2-NH2
1-aminopropane – primary
3) CH3-NH-CH2-CH3
-secondary
2) CH3- CH -CH3
2-aminopropane – primary
4) CH3
-tertiary
|
\
NH2
CH3 - N – CH3
AMIDE
NAMING OF AMIDES
1)
2)
3)
Eg.
Locate the carbonyl group and name the parent carboxylic acid.
Replace the “oic acid” with the ending –amide.
A - Primary Amide – if there are two hydrogen atoms bonded to the nitrogen. This name needs no prefix.
B – Secondary Amide – if there is one alkyl group attached to the nitrogen. Name and locate the alkyl
group, use the letter N to indicate that it is bonded to the nitrogen atom.
C – Tertiary Amide – if there are two alkyl groups attached to the nitrogen. Name and locate each alkyl
group alphabetically, use the letter N to locate before each group.
O
||
CH3-CH-C-NH2
|
CH3
2-methylpropanamide
O
||
CH3-CH2-CH2-C-NH-CH2-CH3
N-ethylbutanamide
O
||
CH3-C-N-CH3
\
CH2-CH3
N-ethyl-N-methylethanamide
EXERCISE
1. Name and classify the following amides.
a)
O
||
CH3-CH2-CH-CH2-C-NH2
|
CH2-CH3
3-ethylpentanamide – 1o
b)
O
||
CH3-CH-CH-C-NH-CH3
| |
CH3 CH3
N – methyl-2,3-dimethylbutanamide
2O
c)
O
||
CH3 –CH2-C-N-CH2-CH2-CH3
\
CH2-CH2-CH3
N,N - dipropylpropanamide
3O
2. Give the condensed structural formulas for the following amides – classify each.
a) N-methylpentanamide
b) N,N-diethylbutanamide
CH3-CH2-CH2-CH2-CO-NH-CH3 CH3-CH2-CH2-CO-NH-CH2-CH3
2O
\
O
3
CH2-CH3
c) hexanamide
CH3-CH2-CH2-CH2-CH2-CO-NH2
1O