1. Alcohols and Phenols King Saud University Chemistry Department

2. King Saud University
Chemistry Department
Alcohols and Phenols
- Alcohols and phenols may be viewed as organic derivatives of water.
H-O-H R-O-H Ar-O-H
Water Alcohol Phenol
- Alcohols and phenols have a common functional group, the hydroxyl group, —OH.
- In alcohols the hydroxyl group is attached to an alkyl group, —R.
- In phenols the hydroxyl function is attached to an aromatic ring, Ar.
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3. Classification and Nomenclature of Alcohols
King Saud University
Chemistry Department
Classification and Nomenclature of Alcohols
Alcohols are classified into:
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4. 2. If a molecule contains both an -OH group and a C=C or C-C
King Saud University
Chemistry Department
IUPAC Name:
In the IUPAC system, alcohols are named according to the following rules:
Select the longest continuous carbon chain that contains the -OH group. Replace the ending e of the alkane by the suffix –ol
2. If a molecule contains both an -OH group and a C=C or C-C
triple bond,
The name should include both the hydroxyl and the unsaturated
groups.
The -OH group takes preference before the double or triple
bonds in getting the lower number.
If a compound contains both OH and a double or triple
bond, choose the chain that include them both even if this is
not the longest chain.
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5. The suffix triol is added when there are three OH groups.
King Saud University
Chemistry Department
3. In the IUPAC system
The suffix diol is added to the name of the parent hydrocarbon when there are two OH groups.
The suffix triol is added when there are three OH groups.
Common name
listing the alkyl substitutents attached to the hydroxyl group, followed by the word alcohol.
Two OH groups on adjacent carbons are known as 1,2-glycols.
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6. - Primary alcohol King Saud University Chemistry Department CH3OH
CH3CH2OH
CH2=CHCH2OH
Common
Methyl alcohol
Ethyl alcohol
Allyl alcohol
IUPAC
Methanol
Ethanol
2-Propen-1-ol
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7. Secondary and tertiary alcohol
King Saud University
Chemistry Department
Secondary and tertiary alcohol
Common
Isopropyl alcohol
Cyclopentyl alcohol
Methylcyclohexyl alcohol
IUPAC
2-Propanol
Cyclopentanol
1-Methyl-1-cyclohexanol
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8. Benzyl alcohol (common name) 2-Phenylethanol
King Saud University
Chemistry Department
Phenol
1-Phenylmethanol
Benzyl alcohol (common name)
2-Phenylethanol
Ethan-1,2-diol
Ethelene glycol (common name)
4-Methyl-2-cyclohexen-1-ol
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9. Physical Properties of Alcohols
King Saud University
Chemistry Department
Physical Properties of Alcohols
Diols and triols are more soluble in water than monohydroxyalcohols.
As the number of carbons in the alcohol increases, the solubility in water decreases.
The boiling points increase with increase in molecular weights.
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10. Alcohols are week acids.
King Saud University
Chemistry Department
The presence of the hydrogen bonding between alcohol molecules as a result of the high b.p. of alcohol.
Alcohols are week acids.
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11. King Saud University
Chemistry Department
Homework
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12. Synthesis (Preparation) of Alcohols
King Saud University
Chemistry Department
Synthesis (Preparation) of Alcohols
1. From alkene
2. From – alkyl halid
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13. 3. Reduction of aldehyde, ketone and carboxylic acid.
King Saud University
Chemistry Department
3. Reduction of aldehyde, ketone and carboxylic acid.
4. Addition of Grignard compounds to aldehyde and ketone.
Tertiary alcohol
Secondary alcohol
Primary alcohol
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14. B. Substitution Reaction
King Saud University
Chemistry Department
Reactions of Alcohols
Reaction as acids (Breaking of oxygen- Hydrogen bond CO ـــــH)
A. Salt Formation
Sodium ethoxide
B. Ester Formation
2. Reaction with CــــOH bond cleavage
A. Elimination Reactions
B. Substitution Reaction

15. 3. Oxidation Reactions King Saud University Chemistry Department

16. Nomenclature and acidity of Phenols
King Saud University
Chemistry Department
Nomenclature and acidity of Phenols
Phenols are generally named as derivatives of the simplest member of the family, phenol (hydroxyl group attached directly to a benzene ring are called phenols).
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17. Alcohols and phenols have weak acidic properties.
King Saud University
Chemistry Department
Introduction of electron-withdrawing groups, such as NO2 or CN, on the ring increases the acidity of phenols.
Alcohols and phenols have weak acidic properties.
Phenols are much stronger acids than alcohols.
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18. Synthesis of Phenols King Saud University Chemistry Department

19. Reactions of Phenols King Saud University Chemistry Department

20. Electrophilic Substitution Reaction
King Saud University
Chemistry Department
Electrophilic Substitution Reaction
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21. King Saud University
Chemistry Department
Home Work
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22. 4) The IUPAC name of 5) The IUPAC name of is: A) 4-Ethyl-5-heptyn-3-ol
King Saud University
Chemistry Department
4) The IUPAC name of
is:
A) 4-Ethyl-5-heptyn-3-ol
B) 4-Ethyl-5-heptan-3-ol
C) 4-Ethyl-5-hepten-3-ol
D) 4-Etyl-2-hepten-5-ol
5) The IUPAC name of
is:
A) 3-Methyl-1-bromocyclohexanol
B) 2-Bromo-3-methylcyclohexanol
C) 4-Bromo-2-methylcyclohexanol
D) 3-Bromo-1-methylcyclohxanol
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23. 6) The common name of 2-methyl-2-propanol is:
King Saud University
Chemistry Department
6) The common name of 2-methyl-2-propanol is:
A) Allyl alcohol
B) Isopropyl alcohol
C) tert-Butyl alcohol
D) Benzyl alcohol
7) The following reaction gives
A) 4-Ethylphenol
B) 2-Ethylphenol
C) Ethylphenyl ether
D) Ethylphenyl ketone
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