NOR AKMALAZURA JANI

• Nomenclature of alcohols, phenols.
• Classification of alcohols.
• Physical properties of alcohols:
- Physical state
- Boiling points
- Solubility of alcohols in water
• Acidity of alcohols and phenols
• Reactions of alcohols:
- Reaction with sodium
- Oxidation
- Esterification
- Halogenation and haloform reactions
- Dehydration
- Formation of ether (Williamson ether synthesis)

• Reactions of phenols:
- Reaction with sodium
- Esterification
- Halogenation of the ring
- Nitration of the ring
• Tests to distinguish classes of alcohols: i) Lucas test ii) Oxidation
• Haloform test to identify methyl alcohol group
- Iodoform
- Bromoform
• Uses of alcohols and phenols.

• Alcohols : Organic compounds containing hydroxyl (-OH) functional groups.
R OH
 Phenols : Compounds with hydroxyl group bonded directly to an aromatic (benzene) ring.
OH

1.
Select the longest continuous chain of carbon atoms containing the hydroxyl group.
2.
Number the carbon atoms in this chain so that the one bonded to the –OH group has the lowest possible number.
3.
Form the parent alcohol name by replacing the final –e of the corresponding alkane name by –ol . When isomers are possible, locate the position of the –OH by placing the number (hyphenated) of the carbon atom to which the –OH is bonded immediately before the parent alcohol name.
4.
Name each alkyl branch chain (or other group) and designate its position by number.

4
3
2 1

4
3
2
3-methyl-2-butanol
1

5 4 3
2 1

5 4
2 1
3-methyl-2-pentanol

• Using the prefix cyclo-
• The hydroxyl group is assumed to be on C1.
H
OH
6
5
4
3
1
2
H
Br
trans-2-bromocyclohexanol IUPAC name: new IUPAC name: trans-2-bromocyclohexan-1-ol
HO CH
2
1
CH
3
3 2
1-ethylcyclopropanol
1-ethylcyclopropan-1-ol

• Alcohol containing double and triple bonds:
- use the –ol suffix after the alkene or alkyne name.
• The alcohol functional group takes precedence over double and triple bonds, so the chain is numbered in order to give the lowest possible number to the carbon atom bonded to the hydroxyl group.
• The position of the –OH group is given by putting its number before the –ol suffix.
• Numbers for the multiple bonds were once given early in the name.

EXAMPLE
5
CH
2
4 3
CH CH
2
2 1
CH CH
3
OH
1) Longest carbon chain that contains –OH group
- 5 carbon
2) Position of –OH group
- Carbon-2
3) Position of C=C
- Carbon-4
COMPLETE NAME = 4-penten-2-ol

• Some consideration:
- OH functional group is named as a hydroxy substituent when it appears on a structure with a higher priority functional group such as acids, esters, aldehydes and ketones.
- Examples:
4
CH
3
3
OH
CH
2
CH
2
1
O
C OH
3-hydroxybutanoic acid
OH
4
5
3
6
2
1
O
2-hydroxycyclohexanone

decreasing priority
MAIN GROUPS
Acids
Esters
Aldehydes
Ketones
Alcohols
Amines
Alkenes
Alkynes
Alkanes
Ethers
Halides

• Alcohols with two –OH groups are called diols or glycols.
• Naming of diols is like other alcohols except that the suffix diol is used and two numbers are needed to tell where the two hydroxyl groups are located.
IUPAC name
OH
3
CH
3
2
CH
1
CH
2 propane-1,2-diol
OH
5
1
OH
4
3
2 OH
trans-cyclopentane-1,2-diol

• The terms ortho (1,2-disubstituted), meta (1,3-disubstituted) and para (1,4-disubstituted) are often used in the common names.
OH
IUPAC name:
Br
2-bromophenol common name: ortho-bromophenol
OH
O
2
N OH
3-nitrophenol
meta-nitrophenol
CH
3
CH
2
4-ethylphenol
para-ethylphenol

• Phenols may be monohydric, dihydric or trihydric according to the number of hydroxyl groups present in the benzene ring.
OH
OH
OH benzene-1,3-diol
OH benzene-1,4-diol
OH
OH
OH benzene-1,2,3-triol

•
According to the type of carbinol carbon atom (C bonded to the –OH group).
C OH
 Classes: i) Primary alcohol
- -OH group attached to a primary carbon atom ii) Secondary alcohol
- -OH group attached to a secondary carbon atom iii) Tertiary alcohol
- -OH group attached to a tertiary carbon atom

i)
TYPE STRUCTURE EXAMPLES
Primary (1°)
R
H
C
H
OH CH
3
CH
2
-OH ethanol
CH
3
CH
3
CHCH
2
OH
2-methyl-1-propanol ii)
Secondary (2°) iii)
Tertiary (3°)
R
R
R'
C
H
OH
R'
C
R''
OH
OH
H
3
C CH CH
2
CH
3
2-butanol
OH cyclohexanol
H
3
C
CH
3
C OH
CH
3
2-methyl-2-propanol

• Alcohols that contain more than one OH group attached to different carbons are called polyhydroxy alcohols.
• Monohydroxy: one OH group per molecule.
• Dihydroxy: two OH groups per molecule.
• Trihydroxy: three OH groups per molecule.

• PHYSICAL STATES OF ALCOHOLS
- simple aliphatic alcohols and lower aromatic alcohols (such as phenylmethanol, C
6
H
5
CH
2
OH) → liquids at room temperature.
- highly branched alcohols and alcohols with twelve or more carbon atoms → solids.

• BOILING POINTS
- The boiling points of alcohols are higher than those of alkanes and chloroalkanes of similar relative molecular mass.
- For example:
C
2
H
5
OH CH
3
CH
2
CH
3
CH
3
Cl
Relative molecular mass: 46
Boiling point: 78 ° C
44
-42 ° C
50.5
-24 ° C
Reason : intermolecular hydrogen bonds exist between the –OH groups in the alcohol molecules.
R Ar
H
δ-
O
δ+
H
O
δhydrogen bonding
R
H
δ-
O
δ+
H
O
δhydrogen bonding
Ar
- Branched chain alcohols boils at a lower temperature (more volatile) than the straight chain alcohols with the same number of carbon atoms.

• SOLUBILITY OF ALCOHOLS IN WATER i) alcohols with short carbon chains (such as methanol, ethanol, and propanol) dissolve in water.
- when alcohols dissolve in water, hydrogen bonds are formed between the –OH group of the alcohol molecule and the –OH group of the water molecule.
ii) the solubility of alcohols in water decreases sharply with the increasing length of the carbon chain. Higher alcohols are insoluble in water.
- alcohol contains a polar end (-OH group) called ‘hydrophilic’ and a nonpolar end (the alkyl group) called ‘hydrophobic’.
- the water solubility decreases as the alkyl group becomes larger.

iii) alcohols with more than one hydroxyl group (polyhydroxy alcohols) are more soluble than monohydroxy alcohols with the same number of carbon atoms. This is because they can form more hydrogen bonds with water molecule. iv) branched hydrocarbon increases the solubility of alcohol in water.
- reason: branched hydrocarbon cause the hydrophobic region becomes compact.
* Phenol is unusually soluble (9.3%) because of its compact shape and the particularly strong hydrogen bonds formed between phenolic –
OH groups and water molecules.

• Alcohol is weakly acidic.
• In aqueous solution, alcohol will donated its proton to water molecule to give an alkoxide ion (R-O ).
R-OH + H
2
O R-O + H
3
O + alkoxide ion
K a
= ~ 10 -16 to 10 -18
Example
CH
3
CH
2
-OH + H
2
O CH
3
CH
2
-O + H
3
O +
 The acid-dissociation constant, Ka, of an alcohol is defined by the equilibrium
R-OH + H
2
O
Ka
Ka = [H
3
O + ] [RO ]
[ROH]
R-O + H
3
O + pK a
= - log ( K a
)
* More smaller the pK a value, the alcohol is more acidic

• Phenol is a stronger acid than alcohols and water.
R-OH + H
2
O alcohol phenol
OH
H
2
O + H
2
O
H
2
O
R-O + H
3
O + alkoxide ion
K a
= ~ 10 -16 to 10 -18
O
phenoxide ion
H
3
O
+ K a
= 1.2 x 10 -10
HO + H
3
O + hydroxide ion
K a
= 1.8 x 10 -16

• Phenol is more acidic than alcohols by considering the resonance effect .
i) The alkoxide ion (RO )
- the negative charge is confined to the oxygen and is not spread over the alkyl group.
- this makes the RO ion less stable and more susceptible to attack by positive ions such as H + ions.

ii) The phenoxide ion
- one of the lone pairs of electrons on the oxygen atom is delocalised into the benzene ring.
- the phenoxide ion is more stable than the alkoxide ion because the negative charge is not confined to the oxygen atom but delocalised into the benzene ring.
- the phenoxide ion is resonance stabilised by the benzene ring and this decreases the tendency for the phenoxide ion to react with H
3
O + .
O O O
O

• The acidity decreases as the substitution on the alkyl group increase.
- Reason: a more highly substituted alkyl group inhibits solvation of the alkoxide ion and drives the dissociation equilibrium to the left.
- For example: methanol is more acidic than t-butyl alcohol.
• The present of electron-withdrawing atoms enhances the acidity of alcohols.
- Reason: the electron withdrawing atom helps to stabilize the alkoxide ion.
- For example: 2-chloroethanol is more acidic than ethanol because the electron-withdrawing chlorine atom helps to stabilize the 2-chloroethoxide ion.
- alcohol with more than one electron withdrawing atoms are more acidic. For example, 2,2,-dichloroethanol is more acidic than 2-chloroethanol.
- Example of electron-withdrawing atom/groups:
Halogen atoms and NO
2
.

• Reaction with sodium
• Oxidation
• Esterification
• Halogenation and haloform reactions
• Dehydration
• Formation of ether (Williamson ether synthesis)

• Alcohols reacts with Na at room temperature to form salts (sodium alkoxides) and hydrogen.
2R-OH + 2Na → 2R-O Na + + H
2
 For example:
CH
3
CH
2
OH + Na → CH
3
CH
2
O Na + + 1/2H
2 alcohol sodium ethoxide
 Reactivity of alcohols towards the reactions with sodium:
CH
3
> 1 ° > 2° > 3°

1 ° alcohol
H
R C O H
Pyridinium chlorochromate (PCC)
CH
2
Cl
2
, 25 o
C
H
1 o
alcohol
H
R-C=O aldehyde
H
R C O H
Cu or Cr
3
O/pyridine
H
1 o
alcohol
Cr
3
O/pyridine = Collins reagent
H
R C OH
H
1 o
alcohol
KMnO
4
/H
+
or K
2
Cr
2
O
7
/H
+ or CrO
3
/H
+
H
R-C=O aldehyde
O
R-C-OH carboxylic acid

Examples:
1 ° alcohol
PCC
CH
3
(CH
2
)
4
-CH
2
-OH
1-hexanol
CH
3
(CH
2
)
4
-CH
2
-OH
1-hexanol
KMnO
4
/H
+
or K
2
Cr
2
O
7
/H
+ or CrO
3
/H
+
O
CH
3
(CH
2
)
4
-C-H hexanal
O
CH
3
(CH
2
)
4
-C-OH hexanoic acid

2 ° alcohol
H
R C O H
R'
2 o
alcohol
KMnO
4
/H
+
or K
2
Cr
2
O
7
/H
+ or CrO
3
/H
+
O
R-C-R' ketone
3 ° alcohol
R"
R C OH
R'
3 o
alcohol
Example:
OH
CH
3
CH CH
2
CH
3
2-butanol
KMnO
4
/H
+
or K
2
Cr
2
O
7
/H
+ or CrO
3
/H
+
KMnO
4
/H
+
or K
2
Cr
2
O
7
/H
+ or CrO
3
/H
+ no reaction
O
CH
3
C CH
2-butanone
2
CH
3

• Esterification:
- the reaction between an alcohol and a carboxylic acid to form an ester and H
2
O.
O O
H
+
R C O H H O R' R C O R' H
2
O carboxylic acid alcohol ester
EXAMPLES
O
CH
3
CH
2
-O -H CH
3 ethanol
C O ethanoic acid
H
O
H
+
CH
3
-O -H C OH
H
+ methanol
H + = catalyst benzoic acid
O
CH
3
C OCH
2
CH
3 ethyl ethanoate
O
C OCH
3
H
2
O methyl benzoate
H
2
O

Esterification also occurs when alcohols react with derivatives of carboxylic acids such as acid chlorides
CH
3
-OH methanol
O
CH
3
C Cl ethanoyl chloride
O
CH
3
C OCH
3 methyl ethanoate
HCl

1) Hydrogen halides (HBr or HCl or HI)
R-OH + H-X → R-X + H
2
O
Example:
C
2
H
5
OH + H-Br C
2
H
5
Br + H
2
O
•
+
Reactivity of hydrogen halides decreases in order HI > HBr > HCl
• Reactivity of alcohols with hydrogen halides:
3 ° > 2 ° > 1 °

2) Phosphorus trihalides, PX
3
3R-OH + PX
3
(PX
3
= PCl
3 or PBr
3
3R-X + H
3
PO
3 or PI
3
)
Example:
(CH
3
)
2
CHCH
2
OH + PBr isobutyl alcohol
3
→ (CH
3
)
2
CHCH
2
Br isobutyl bromide
3) Thionyl chloride (SOCl
2
)
R-OH + SOCl
2
→ R-Cl + SO
2
+ HCl
Example:
CH
3
(CH
2
)
5
CH
2
1-heptanol
OH + SOCl
2
→ CH
3
(CH
2
)
5
CH
2
Cl
1-chloroheptane
+ SO
2
+ HCl

• Dehydration of alcohols will formed alkenes and the products will followed Saytzeff rules.
conc. H
2
SO
4
R-CH
2
-CH
2
-OH R-CH=CH
2
+ H
2
O
 Saytzeff rule:
- A reaction that produces an alkene would favour the formation of an alkene that has the greatest number of substituents attached to the C=C group.
H
+
CH
3
CH
2
-CH-CH
3
OH H
+
CH
3
CH
2
-CH=CH
1-butene
2
+ H
2
O
CH
3
CH=CH-CH
3
+ H
2
O
2-butanol
2-butene major product

• Reactivity of alcohols towards dehydration:
3 ° > 2 ° > 1 °
• Reagents for dehydration: i) Concentrated H
2
SO
4 conc. H
2
SO
4
CH
3
-CH
2
-OH CH
2
=CH
2
+ H
2
O ii) With phosphoric (v) acid
OH
85% H
3
PO
4
, 165-170 o
C H
2
O iii) Vapour phase dehydration of alcohols
CH
3
CH
2
OH
Al
2
O
3 heat
CH
2
=CH
2
+ H
2
O

Formation of ether (Williamson ether synthesis)
• Involves the S
N
2 attack of an alkoxide ion on an unhindered primary alkyl halides.
• The alkoxide is made by adding Na, K or NaH to the alcohol.
R-O + R’-X → R-O-R’ + X alkoxide
(R’ must be primary)


The alkyl halides (or tosylate) must be primary, so that a back-side attack is not hindered.
If the alkyl halides is not primary, elimination usually occurs to form alkenes.

EXAMPLES
CH
3
CH
2
-OH Na CH
3
CH
2
-O Na
+
CH
3
I
CH
3
CH
2
-O H
1) Na
2) CH
3
I or
CH
3
CH
2
-O-CH
3
NaI
CH
3
CH
2
-OCH
3
NaI
O H
1) Na
2) CH
3
CH
2
-OTs cyclohexanol
O CH
2
CH ethoxycyclohexane
3

• Reaction with sodium
• Esterification
• Halogenation of the ring
• Nitration of the ring

REACTION WITH SODIUM
OH Na O
-
Na
+ sodium phenoxide
1/2 H
2
(g)
REACTION WITH AQUEOUS SODIUM HYDROXIDE
O H Na OH O
-
Na
+ sodium phenoxide
H
2
O
ROH + NaOH no reaction

EXAMPLES
OH
O H
NaOH
H
2
O
O Na sodium phenoxide
O
CH
3
C Cl
NaOH
O
C OH
H +
O
OC phenyl benzoate
O
OCCH
3
NaCl
H
2
O

• More reactive towards electrophilic substitution than benzene.
• ortho-para director.
OH
OH
X X room
3X
2
3HX temperature
X
EXAMPLES
OH
OH
Br Br
3Br
2 room temperature
3HBr
Br
2,4,6-tribromophenol (white precipitate)
OH
OH
Cl Cl
3Cl
2 room temperature
3HCl
Cl
2,4,6-trichlorophenol (white precipitate) monobromophenols are obtained if the bromine is dissolved in a non-polar solvent such as CCl
4
OH
OH OH
2
2Br
2
(CCl
4
)
Br
2HBr
Br

2
• Monobromophenols are obtained if the bromine is dissolved in a non-polar solvent such as CCl
4.
OH
OH
Br
OH
2Br
2
(CCl
4
) 2HBr
Br

• Dilute nitric (v) acids reacts with phenol at room temperature to give a mixture of 2- and 4-nitrophenols.
2
OH
2HNO
3
< 20 o
C
OH
NO
2
OH
2-nitrophenol
NO
2
4-nitrophenol
2H
2
O

 By using concentrated nitric (v) acid, the nitration of phenol yields 2,4,6-trinitrophenol (picric acid).
 Picric acid is a bright yellow crystalline solid. It is used in the dyeing industry and in manufacture of explosives.
OH
O
2
N
OH
NO
2
3HNO
3
3H
2
O
NO
2
2,4,6-trinitrophenol
(picric acid)

1) Lucas Test
- The alcohol is shaken with Lucas reagent (a solution of ZnCl
2 in concentrated HCl).
Tertiary alcohol - Immediate cloudiness (due to the formation of alkyl chloride).
Secondary alcohol - Solution turns cloudy within about 5 minutes.
Primary alcohol - No cloudiness at room temperature.

CH
3
CH
3
C CH
OH
3 o
alcohol
3
CH
3
HCl/ZnCl
2 room temperature
CH
3
C CH
3
Cl
(cloudy solution almost immediately)
CH
3
CH CH
2
CH
3
OH
2 o
alcohol
HCl/ZnCl
2 room temperature
CH
3
CH CH
2
CH
3
Cl
(cloudy solution within 5 minutes)
CH
3
CH
2
CH
2
CH
2
OH
1 o
alcohol
HCl/ZnCl
2 room temperature no reaction

2) Oxidation of alcohols
- only primary and secondary alcohols are oxidised by hot acidified KMnO
4 or hot acidified K
2
Cr
2
O
7 solution.
- the alcohol is heated with KMnO of dilute H
2
SO
4
.
- 1 o or 2 o alcohol:
4 or K
2
Cr
2
O
7 in the presence
→ the purple colour of KMnO
4
→ the colour of the K green .
2
Cr
2
O
7 solution disappears .
solution changes from orange to
- 3 o alcohol do not react with KMnO
4 or K
2
Cr
2
O
7
.

3RCH
2
OH + Cr
2
O
2-
7
+ 8H
+
1 o
alcohol (orange)
3RCHO + Cr
2
O
2-
7
+ 8H
+ aldehyde (orange)
3RCHO + 2Cr
3+
+ 7H
2 aldehyde (green)
3RCOOH + 2Cr
3+
+ 7H
2
O carboxylic acid (green)
O
R'
3 R CH OH
2 o
alcohol
+ Cr
2
O
2-
7
+ 8H
+
(orange)
3
R'
R C ketone
O + 2Cr
3+
+ 7H
2
O
(green)

HALOFORM TEST TO IDENTIFY METHYL
ALCOHOL GROUP
1) Iodoform:
• Ethanol and secondary alcohols containing the group methyl alcohol group which react with alkaline solutions of iodine to form triiodomethane (iodoform, CHI
3
).
• Triiodomethane – a pale yellow solid with a characteristic smell.
CH
3
H
C
OH
(methyl alcohol group)

CH
3
H
C R + 4I
2
+ 6NaOH
OH
CHI
3
(s) + RCOONa + 5NaI + 5H
2
O triiodomethane
(iodoform) yellow precipitate where R = hydrogen, alkyl or aryl group
• The iodoform test can distinguish ethanol from methanol
H
O
CH
3
C H + 4I
2
+ 6OH CHI
3
(s) + 5I
-
+ 5H
2
O H C O iodoform methanoate
OH ethanol positive iodoform test
H
H C H + 4I
2
+ 6OH
OH methanol no reaction negative iodoform test

• The iodoform test can distinguish 2-propanol from 1-propanol
CH
3
CH
3
C H + 4I
2
+ 6OH
OH
2-propanol
CHI
3
(s) + 5I
-
+ 5H
2
O iodoform
CH
3
O
C ethanoate positive iodoform test
O
H
H H H
C C C H + 4I
2
+ 6OH
H H OH
1-propanol no reaction negative iodoform test
* TERTIARY ALCOHOLS DO NOT GIVE POSITIVE
IODOFORM TEST

2) BROMOFORM
CH
3
H
C R + 4Br
2
+ 6NaOH
OH where R = hydrogen, alkyl or aryl group
CHBr
3
(s) + RCOONa + 5NaBr + 5H
2
O bromoform sample reagent iodoform

• As solvents:
- examples: the lower alcohols such as methanol, ethanol and propanol.
- methanol is used as a solvent for varnish and paints.
• As fuels:
- biofuel (fuel derived from a biological source).
- ethanol can be produced from sugars such as sucrose from sugar cane, through fermentation and distillation. It can be blended with petrol and used as fuel in motor vehicles.
- methylated spirit is ethanol made undrinkable by the addition of a little methanol. It is used as a fuel in camping stoves.

• In alcoholic drinks:
- ethanol is used for making wine, beer and etc.
• As intermediates:
- methanol can be oxidised to methanal (HCHO), a chemical feedstock (starting material) for the manufacture of thermosetting plastics such as bakelite.
- methanol is used to make methyl methacrylate which is used in the manufacture of another plastic called perspex.
• In cosmetics:
- ethanol is used as solvent for fragrances in perfumes and aftershave lotions.
- polyhydroxyl alcohols (for example, glycerol) are used in moisturising creams.

• Making plastics such as bakelite (phenol-methanal plastic).
• The synthesis of cyclohexanol and hexanedioic acid to make nylon 6,6.
• Making dyes.
• Making antiseptics such as 4-chloro-3,5dimethylphenol which is active ingredient in
‘Dettol’.