1. Alcohols and Phenols 1

2. know the difference in structure between alcohols and phenols
Learning Objectives
Chapter six concerns alcohols and phenols and by the end of this chapter the student will:
know the difference in structure between alcohols and phenols
Know the different classes of alcohols
Know how to name alcohols and phenols
Know the physical properties (solubility, boiling and melting points)
Know how hydrogen bonds are formed and its effect on boiling points of alcohols
Know the acidic properties of alcohols and phenols
know the different methods that can be used to prepare alcohols and phenols.
Know the chemical reactions of these compounds ( some reactions are review, others are extensions of the chemistry that will be discussed on chapters 8, 9 & 10
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3. H-O-H R-O-H or PhCH2OH Ph-O-H
Alcohols and Phenols
Structure Of Alcohols and Phenols
Alcohols and phenols may be viewed as organic derivatives of water.
H-O-H R-O-H or PhCH2OH Ph-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 directly attached to benzene ring
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4. Classification and Nomenclature of Alcohols
Alcohols and Phenols
Classification and Nomenclature of Alcohols
Alcohols are classified according to the type of the carbon atom connected to the hydroxyl group (carbinol carbon) into:
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5. NOMENCLATURE OF ALCOHOLS
Alcohols and Phenols
NOMENCLATURE OF ALCOHOLS
IUPAC Nomenclature Of Alcohols
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 cΞc bond;
Choose the chain that include both of them even if this is not the longest chain.
The name should include suffixes indicate presence of both the OH group and the unsaturated groups.
The OH group takes precedence over the double or triple bonds in getting the lower number.
Cyclic alcohols are named using the prefix cyclo-, the carbon bearing the hydroxyl group is assumed to take number 1.
3. The suffix diol is added to the name of the parent hydrocarbon when there are two OH groups.
4. The suffix triol is added when there are three OH groups.
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6. Common Nomenclature Of Alcohols
Alcohols and Phenols
Common Nomenclature Of Alcohols
List the names of alkyl substituents attached to the hydroxyl group, followed by the word alcohol.
If two OH groups present on two adjacent carbons these known as glycols
Primary alcohols
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 alcohols
Alcohols and Phenols
Secondary and tertiary alcohols
Common
Isopropyl alcohol
Cyclopentyl alcohol
Methylcyclohexyl alcohol
IUPAC
2-Propanol
Cyclopentanol
1-Methyl-1-cyclohexanol
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8. Examples Alcohols and Phenols 1-Phenylmethanol 2-Phenylethanol
Benzyl alcohol (common name)
2-Phenylethanol
4-Methyl-2-cyclohexen-1-ol
Ethan-1,2-diol
Ethelene glycol (common name)
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9. Alcohols and Phenols
Examples
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10. Physical Properties of Alcohols
Alcohols and Phenols
Physical Properties of Alcohols
1) Boiling Points of Alcohols
The boiling points increase with increase in molecular weights.
Alcohols have higher boiling points(b .p.) than alkanes of similar weight this is due to the presence of hydrogen bonds between molecules of alcohols.
hydrogen bond
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11. Homework 2) Solubility Of Alcohols and Phenols
Alcohol and water contain hydroxyl group that can form hydrogen bonds.
The hydroxyl group is hydrophilic “water loving”
The alkyl group of alcohols is hydrophobic “ water hating”
As the number of the –OH group in alcohol increases, the solubility in water increases.
Diols and triols are more soluble in water than monohydroxyalcohols.
The lower alcohols are completely miscible with water
As the number of carbons in the alcohol increases, the solubility in water decreases.
Homework
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12. 3) Acidic Properties of Alcohols: Alcohols are very weak acids
Alcohols and Phenols
3) Acidic Properties of Alcohols:
Alcohols are very weak acids
The hydroxyl proton of an alcohol is weakly acidic
A strong base can abstract the hydroxyl proton to give an alkoxide ion.
Electron-withdrawing group (-I) increase acidity
Electron-releasing group (+I) decrease acidity
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13. Synthesis (Preparation) of Alcohols 1- Hydration From Alkenes
Alcohols and Phenols
Synthesis (Preparation) of Alcohols
1- Hydration From Alkenes
1- Oxidation of Alkenes
2- From alkyl halide
(elimination of HX using
base gives alkene)
nucleophilic substitution
or aq. KOH
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14. 3- Reduction of aldehydes, ketones and carboxylic acids
Alcohols and Phenols
3- Reduction of aldehydes, ketones and carboxylic acids
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15. 4- Addition of Grignard compounds to aldehydes & ketones
Alcohols and Phenols
4- Addition of Grignard compounds to aldehydes & ketones
Tertiary alcohol
Ketone
Secondary alcohol
Primary alcohol
Methanal
formaldehyde
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16. 1. Dissociation of O-H Bond
Alcohols and Phenols
Reaction of Alcohols
1. Dissociation of O-H Bond
Reaction as acids (Breaking of oxygen- Hydrogen bond CO ـــــH)
A. Formation of Salt (Alkoxide formation)
Sodium ethoxide
B. Formation of Esters H+
H+/ H2O
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17. 2. Dissociation of C-O Bond Reaction with CــــOH bond cleavage
Alcohols and Phenols
2. Dissociation of C-O Bond
Reaction with CــــOH bond cleavage
A. Elimination Reactions
B. Substitution Reaction
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18. Alcohols and Phenols
C. Oxidation Reactions
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19. Nomenclature and acidity of Phenols
Alcohols and Phenols
Nomenclature and acidity of Phenols
Phenols (compounds having hydroxyl group directly attached to a benzene ring ) are generally named as derivatives of the simplest member of the family, phenol
Acidity :
Alcohols and phenols have weak acidic properties.
Phenols are much stronger acids than alcohols.
Introduction of electron-withdrawing groups, such as NO2 or CN, on the ring increases the acidity of phenols.
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20. Alcohols and Phenols
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21. Alcohols and Phenols
Synthesis of Phenols
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22. Alcohols and Phenols
Reactions Phenols
Ethers formation
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23. 2. Electrophilic Substitution Reactions
Alcohols and Phenols
2. Electrophilic Substitution Reactions
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24. Alcohols and Phenols
Home Work
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25. 4) The IUPAC name of is: A) 4-Ethyl-5-heptyn-3-ol
Alcohols and Phenols
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
6) The most acidic compound is:
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26. 7) The common name of 2-methyl-2-propanol is: A) Allyl alcohol
Alcohols and Phenols
7) The common name of 2-methyl-2-propanol is:
A) Allyl alcohol
B) Isopropyl alcohol
C) tert-Butyl alcohol
D) Benzyl alcohol
8) The following reaction gives
A) 4-Ethylphenol
B) 2-Ethylphenol
C) Ethylphenyl ether
D) Ethylphenyl ketone
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27. Alcohols and Phenols
9) The major product for the following reaction is
10) The product of the reaction shown below is
11) Which of the following compounds has the highest boiling point?

28. Thank You for your kind attention !
Alcohols and Phenols
Thank You for your kind attention !
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