Alcohols, Phenols and Ethers

ABYSS Learning

ALCOHOL, PHENOL & ETHER

ALCOHOL

Hydroxy derivatives

Aliphatic hydroxy derivatives Aromatic hydroxy derivatives

( I ) Aliphatic hydroxy derivatives :

Hydroxy derivatives in which —OH is directly attached to sp3 C (Alcoholic compounds).

(II) Aromatic hydroxy derivatives :

Hydroxy derivatives in which —OH is directly attached to sp2 C or benzene ring (Phenolic compounds).

 Aliphatic hydroxy derivatives :

( a ) Classification according to number of —OH groups :

(i) Monohydric [one –OH]  C H 3C H 2— O H

(ii) Dihydric [two –OH]  CH2 CH2

OH OH

(iiii) Trihydric [three –OH]  CH2 CH CH2
OH OH OH

(iv) Polyhydric [n –OH]  CH2 CH -------------CH2

OH OH OH

( b ) Classification according to nature of carbon : sp 3 :O:
sp 3
(i) p or 1° – alcohol  CH3CH2 – OH
(ii) s or 2° – alcohol  (CH3)2CH – OH
(i) t or 3° – alcohol  (CH3)3C – OH
 Structure of alcohol :

sp3

Alcohols are bent molecules. The carbon atom (linked with 108.5° 1s

'O' atom of –OH group) is sp3 hybridised. The central 'O' H3Csp3 H 1s
atom is also in sp3 state of hybridisation. The bond angle is
108.50 . In sp3 hybridisation of O - 2s2,2px2 2py1 2pz1 Structure of CH3OH
orbitals hybridised to form sp3 orbitals

O      Non - bonding e— pair
2s 2px 2py 2pz
sp3 hybridisation  bond O atom
 bond
In these four orbitals two containing one electron
sp3 +. .×
each and two containing two electrons each.
Orbitals containing two electrons do not take part S H atom
in bonding. Other two half filled orbitals form 
bond with s-orbitals of H -atom and hybridised hybridised 108.5°
orbital of C-atom (O—C).
Due to lone pair effect the bond angle of orbitals sp3 C atom
tetrahedral oxygen atom is lesser than normal
tetrahedral structure (109028'). .× .×
S .×
S
HS H

H

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MONOHYDRIC ALCOHOL

 General methods of preparation :
( a ) From alkanes (By oxidation) :

(CH3)3 C—H H/KMnO4  (CH3)3 C—OH
( b ) From alkenes :

(i) By hydration :

CH3—CH CH2 H CH3 CH CH3
H2O OH

(ii) By hydroboration oxidation :

CH3—CH CH2 BH3  CH3 CH2 CH2 (1° alcohol)

H2O2 HO

OH

(iii) By oxymercuration demercuration :

CH3—CH CH2 (i()iiH)Nga(OBAHc4),2H,HO2O CH3 CH CH3
OH

( c ) From alkyl halides (By hydrolysis) :

CH3—CH2—Cl Aq. KOH CH3CH2—OH

or Moist Ag2O

( d ) From carbonyl compounds (By reduction) :

>C O Reducing agent  >CH—OH

 Reducing agents may be,

LiAlH4/H NaBH4/H
Na + EtOH [Bouveault-blanc Reduction]

NaH [Darzen reduction]

Ni/H2

R—CHO L iAlH 4 R—CH2—OH

H

RCR N a BH 4 R CH R
OH
O H
CH3 C CH3 ?
L iAlH 4
O
 Mechanism : H

HH

CH3 C CH3 H CH3 C  C CH3

LiAlH4 CH3H  CH3

O O OH

OD

H
O LiAlH4

D

OH

D

NaBD4
H

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ABYSS Learning

CH3—CH CH—CHO L iAlH 4 CH3—CH CH—CH2—OH
Crotonaldehyde
H

Ph—CH CH—CHO LiAlH 4 Ph—CH2—CH2—CH2—OH

Cinnamaldehyde H / OH–
( e ) From ethers :

R—O—R dil.H2 SO4 R—OH + R—OH

CH3—O—CH2CH3 dil.H2SO4 CH3—OH + CH3CH2—OH

( f ) From acid and derivatives (By reduction) :

R—COOH L iAlH 4 R—CH2—OH + H2O

H

R C Cl L iAlH 4 R—CH2—OH + HCl
O R—CH2—OH + R—OH
H R—CH2—OH + R—CH2—OH

R C OR L iAlH 4
O
H

R C O C OR LiAlH4

H

OO

R C NH2 L iAlH 4 R—CH2—NH2 +H2O

H

O

( g ) From esters (By hydrolysis) :

(i) By alkaline hydrolysis :

R C OR NaOH  R C ONa + R OH

O O
(ii) By acidic hydrolysis :

R C OR  R C OH + R OH

O 18 H2 O(Hex cess ) O
CH3 C
OC2H5  18

H3 O CH3 C OH + C2H5OH

OO

This reaction is reversible reaction and it's order is 1 and it is also called Pseudo-Unimolecular reaction.
( h ) From p-amines :

R—NH2 NaNO2HCl R—OH + N2 + H2O

or HNO2

C H 3C H 2— N H 2 HNO2 CH3CH2—OH + N2 + H2O
 Mechanism :

 
CH 3 CH2 — NH2 NaNO2HCl CH 3 CH2 — N 2 Cl  CH3 CH2  N2  Cl

(Unstable)

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ABYSS Learning

  CH3CH2 OH [major]
OH CH3CH2 Cl
CH3CH2 CH3CH2 O N O
 CH2 CH2
Cl


O NO


H

Inter mediate is carbocation so rearrangement may be possible.

E x . CH3CH2CH2—NH2 NaNO2HCl ?
Sol. Mechanism :

CH3CH2CH2—NH2 NaNO2HCl  

CH3CH2CH2— N2 Cl  CH3CH2 CH 2

CH3 CH   

CH3HO CH3 CH CH3H

OH

E x c e p t i o n : CH 3 — NH2 HNO2  CH 3 — O — CH 3

(i ) From Grignard reagent :
(i) p-alcohol :

R—Mg—X + [O]  R—O—MgX H2O R—OH
[Same C-p-alcohol]

RR

  X + H C H H C H H2O H C H

R Mg

O OMg X OH [one C more p-alcohol]

  X + CH2 RR
CH2 CH2 CH2 H2O CH2 CH2
R Mg

O OMgX OH

[two C more p-alcohol]

(ii) s-alcohol :

RR
R Mg X + R C H R C H H2O R C H

O OMgX OH

R

R Mg X + H C OR  H C R R MgX H C R

H2O

OO OH

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(iii) t-alcohol :
RR

R Mg X + R C R  R C R H2O R C R

O OMgX OH

R

R Mg X + R C OR R C R R MgX R C R

H2O

OO OH

 Physical properties :

(i) C1 to C11 are colourless liquids and high alcohols are solids.
(ii) Density of monohydric alcohol is less than H2O.

(iii) Density  mol. wt. (for monohydric alcohol).

(iv) Solubility : C1 to C3 and t-butyl alcohol is completely soluble in H2O due to H–bonding.

1

solubility  No. of side chainsc   molecular weight

Order of solubility :

C4H9OH > C5H11OH > C6H13OH

CH3CH2CH2CH2OH < CH3CH2CH OH < CH3
CH3 CH3 C OH

CH3

CH3CH2CH2 < CH3 CH CH2 < CH2 CH CH2
OH OH OH
OH OH OH

[Number of —OH increases, H-bonding increases]

(v) Boiling points : B.P.  molecular weignt

If molecular wt. is same then B.P.  1

branching

Order of BP : C4H9OH < C5H11OH < C6H13OH

CH3CH2CH2CH2OH > CH3CH2CH OH CH3
> CH3 C OH
CH3CH2CH2 CH3 <
OH < CH3 CH CH2 CH3
CH2 CH CH2
OH OH OH OH OH

[Number of OH increases, H-bonding increases]

E x . Boiling point of alcohol is more than corresponding ether. Why ?

S o l . Reason : H-bonding in alcohol.

O H---------- O H------------- O H ------------- O H ----------

RR R R

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ABYSS Learning

E x . Boiling point of alcohol is less than corresponding carboxylic acid. Why ?
S o l . Reason : Dimer formation in carboxylic acid.

O HO
CR
RC
OH O

 Chemical properties :

Monohydric alcohol show following reactions

(A) Reaction involving cleavage of O H

(B) Reaction involving cleavage of C OH

(C) Reaction involving complete molecule of alcohol

( A ) Reaction involving cleavage of O H: Reactivity order (Acidic nature) is

CH3—OH > CH3CH2—OH > (CH3)2CH—OH > (CH3)3C—OH

(i ) Acidic nature :

H2O > R — O H > CH CH > NH3 (Acidic strength)

Alcohols are less acidic than H2O and neutral for litmus paper and gives H2 with active metals (Na, K)

R—OH + Na  1
R—ONa + 2 H2

R—OH + K  1
R—OK + 2 H2

(ii) Reaction with CS2 :  1
R—OH + Na R—ONa + 2 H2

R—ONa + S C S  R O C S Na

S

Sodium alkyl xanthate (Used as floating agent)

(iii) Alkylation:

R—OH CH2N2 R—O—CH2—H

R—OH Na R—ONa R X  R — O — R
(iv) Acylation : (Williamson synthesis)

R OH + Cl C R  ROCR

O O
(Acylation)
R OH + Cl C CH3  R O C CH3
O
O
(Acetylation)

OH CH2COCl OCR
COOH O
COOH

Salicylic acid Acetoxy benzoic acid
Acetyl salicylic acid
Aspirin [Used as analgesic]

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( v) Benzoylation : (Schotten Baumann's Reaction) :

R OH + Cl C Ph  R O C Ph

OO

(Benzoylation)
( v i ) Esterification : Conc. H2SO4 is used as catalyst and dehydrating agent.

R C OH + R OH conc. H2SO4  R C OR + H2O
OO

 Mechanism :

H2SO4     H+ + H SO –
4

::
R—C—O—H + H+ R—C—O—H

O OH



OH OH OH OH +
R—C
R—C—O—H+ ROH R—C—OH  R—C –H R—C—OR'
OH OR'
 R—C—OH2 OR' O

O OR'
H R'

Note : This is a laboratory method to prepare ester.

Example : CH3 C OH + H OC2H5 conc. H2SO4  CH3 C OC2H5 + H2O
OO

Example : Ph C OH + H 18 18
O
OC2H5 conc. H2SO4  Ph C OC2H5 + H2O

O

Dry HCl can be used as dehydrating agent.

Example : CH3 C OH + H OC2H5  Dry.HCl  CH3 C OC2H5 + H2O
OO

1

(i) Reactivity for esterification  Steric hinderence .

(ii) Reactivity of R – OH [If acid is same] : CH3 – OH > 1° > 2° > 3° alcohol
(iii) Reactivity of RCOOH [If alcohol is same] :

CH3

H C OH > CH3 C OH > CH3 CH C OH > CH3 C C OH

O O CH3 O CH3 O

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(vii) Reaction with CH CH :

CH CH + 2CH3—OH BF3/HgO CH3CH OCH3
OCH3

Methylal

CH CH + 2CH3CH2— OH BF3/HgO CH3CH OC2H5
OC2H5

Ethylal

(viii) Reaction with carbonyl compounds :

R—CHO + 2R—OH H OR
R CH

OR
Acetal

R C R + 2R OH H R OR
O C

R OR
Ketal

CH3CHO + 2CH3—OH H CH3CH OCH3
(ix) Reaction with Grignard reagent : OCH3

Methylal

R—Mg—X + H—OR H R X
H + Mg
OR

( x ) Reaction with Ketene : Ketene is used as acetylating agent.

OR OR
CH2 C O + R—OH  CH2 C OH  CH3 C O

OC2H5 OC2H5

CH2 C O + C2H5—OH  CH2 C OH  CH3 C O

Ethylacetate

( x i ) Reaction with isocyanic acid : Ethyl urethane is used in preparation of urea

OC2H5 OC2H5

NH C O + H—OC2H5  NH C OH  NH2 C O

Ethyl urethane

(xii) Reaction with oxirane :
OR

R OH + CH2 CH2 H+  CH2 CH2
O OH

( B ) Reaction involving cleavage of C OH: Reactivity order or basic nature is

CH3—OH < CH3CH2—OH < (CH3)2CH—OH < (CH3)3 C—OH

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(i) Reaction with halogen acid :

R—CH2—OH + HCl ZnCl2  R—CH2—Cl + H2O

R2CH—OH + HCl ZnCl2   R2CH—Cl + H2O
20 alcohol

Reactivity of the acids is HI > HBr > HCl > HF
(ii) Reaction with inorganic acids :

R OH + H O N O  R O N O + H2O

OO

Nitric acid Alkyl nitrate

R—OH + HHSO4  R—HSO4 + H2O
Alkyl hydrogen sulphate

(iii) Reaction with phosphorous halides :

3R—OH + PCl3  3RCl + H3PO3

R—OH + PCl5  R—Cl + POCl3 + HCl

(iv) Reaction with thionyl chloride (SOCl2) :

R—OH + SOCl2 Pyridine  R—Cl + SO2  + HCl

(gas)

( v ) Reaction with NH3 : Alumina (Al2O3) is used as dehydrating agent.

R OH + HNH2 Al2O3  R—NH2 + H2O

250 C

( v i ) Reaction with halogens : Oxidation and chlorination takes place simultaneously.

CH3CH2OH + Cl2(dry)  CH3CHO + 2HCl (Oxidation)

CH3CHO + 3Cl2  CCl3CHO + 3HCl (chlorination)
chloral

(C ) Reaction involving complete molecule of alcohol :

( i ) Dehydration : Removal of H2O by two type
(a) Intermolecularly removal of H2O [form ether]
(b) Intramolecularly removal of H2O [form alkene]

C2H5 OH + H2SO4 0°C (C2H5)2SO4
(conc.) 100°C C2H5HSO4
140°C C2H5 O C2H5 (Williomson's synthesis)
170°C CH2 CH2 (Elimination)

C2H5 OH +Al2O3 250°C C2H5 O C2H5
(Alumina) 350°C CH2 CH2

Ease of dehydration follow the order : 3° ROH > 2° ROH > 1° ROH > CH3OH

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ABYSS Learning

( i i ) Catalytic Dehydrogenation : This reaction is useful in distinction of 1°, 2° and 3° alcohols.

CH3CH2OH 30C0uC CH3CHO + H2
(p- alcohol ) 30C0uC (Acetaldehyde)

CH3 CH CH3 CH3 C CH3 + H2
OH
O
(s- alcohol) (acetone)

CH3 30C0uC CH3

CH3 C OH CH3 C CH2 + H2O [dehydration]
CH3 (Iso - butylene)

(t. alcohol)

( i i i ) Oxidation : This reaction is useful in distinction of 1°, 2° and 3° alcohols.

R—CH2—OH HH/KKM2nCOr24Oo7r  RCHO Room[Ot]emp. RCOOH
(p-alcohol)
(same carbon acid)

R CH R'  [O] No reaction

OH H/KMnO4or R C R Room temp.
(s-alcochol)
H/K2Cr2O7 high temp. Acids (less carbon)

O
(same carbon)

R [O] No reaction

RCR Room temp.

OH high temp. Acids (less carbon)
(t-alcohol)

CH3CH2 CH CH3 high[Ote]mp. CH3CH2 C CH3 [ O ] CH3COOH + CH3COOH
P2O5
OH O

Carbonyl group goes with smaller alkyl group

(i v) Reaction with phosporous pentasulphide :

R—OH + P2S5  R—SH +
Thio alcohol

( v) Reaction with salts :

CH3OH CuSO4 CuSO4. 2CH3OH
CaCl2 CaCl2. 4CH3OH
MgCl2 MgCl2 . 6CH3OH

(vi) Distinction between 1°, 2° and 3° alcohols :

( a ) Lucas test : A mixture of HCl(conc.) and anhydrous ZnCl2 is called Lucas reagent.

p-alcohol ZnCl2 HCl No turbidity at room temp. [On heating within 30 minutes.]

s-alcohol ZnCl2 HCl Turbidity appears within 5 minutes.

t-alcohol ZnCl2 HCl Turbidity appears within 1 minute.

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ABYSS Learning

( b ) Victor - Meyer test : This is colour test for alcohol (pri. sec. & tert.) .

p-alcohol  Red colour

s-alcohol  Blue colour

t-alcohol  No colour

R—CH —OH [1°] R CH—OH [2°] R C—OH [3°]
2 2 3

 P + I2 P + I2 P + I2

R—CH —I R CH—I R C—I
2 2 3

 AgNO2  AgNO2 AgNO2

RCH —NO R CH—NO R C—NO  
22 22 32
 HNO2  HNO2 HNO2

R—C—NO R C—NO No reaction
2 22
N OH N NaOH

NaOH NaOH

Soluble (Red) Insoluble (Blue) Colourless (White)
(vii) Dichromate test :

1° Alcohol HK2Cr2O7  Acid + Cr+3
orange [Cr 6 ] [green]

2° Alcohol HK2Cr2O7  Ketone + Cr+3
orange [Cr 6 ] [green]

3° Alcohol HK2Cr2O7  No oxidation, No green
orange [Cr 6 ]

(v iii) Te st of alcholic group :

R—OH N a  1
R—ONa + H

22

[effervesence of H ]
2

R—OH PCl5  R—Cl + POCl + HCl NH3 NH Cl
3 4

[White fumes]

R — O H Cerric ammonium nitrate  Red colour

( i x ) Distinction between CH3 – OH and C2H5OH

CH OH CH CH OH
3 32

B.P. 65°C 78°C
Yellow ppt of CHI
I + NaOH No ppt
Smell of formalin [HCHO] 3
2
No smell
Cu/300°C No smell

Salicylic acid Smell of oil of wintergreen

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ABYSS Learning

OH CH3OH OH Methyl salicylate
COOH Ph—OH COOH3 (Oil of wintergreen)
CH3COCl
OH Phenyl salicylate
COOPh Salol (Internal antiseptic)

O C CH3 Aspirin
O (Analgesic)
COOH

 Additional reactions :

(a) Oxidation by HIO [per iodic acid] :
4

CH2 CH2 HIO4  CH2 OH + HO CH2 2H2O HCHO + HCHO

OH OH OH OH

CH2 CH CH2 HIO4  HO CH2+HO CH OH + HO CH2 3H2O HCHO+HCOOH+HCHO

OH OH OH OH OH OH
(Glycerol)

 Condition for oxidation by HIO :
4

At least 2 —OH or 2 >C=O or 1 —OH and 1 >C=O should be at adjacent carbons.

CH3 O

Example : CH3 CH CH C CH3 2HIO4 CH3CHO + HCOOH + CH3 C CH3

OH OH OH

Example : CH3 O H HIO4  CH3COOH + CHO CH2 CHO
C CH CH2 C
O OH

Example :

CHO CHO O CHO

O 2HIO4 O COOH +H2O + CO2
O OH + HO C OH–H2O CHO

HO CH2 HO CH2 OH (H2CO3) HO CH2
OH
OH

( b ) Pinacole - Pinacolone Rearrangement :

CH3 CH3 conc. H2SO4  CH3
CH3 C C CH3 CH3 C C CH3

OH OH O CH3

Pinacole Pinacolone

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Mechanism :

CH3 CH3 CH3 CH3 CH3  CH3
CH3 C C CH3 C
H CH3 C C CH3 –H2O CH3 C
OH OH
 CH3
OH OH2 OH

CH3 CH3 CH3

 C CH3

CH3 C C CH3–H CH3 C C CH3 CH3 C

O CH3 OHCH3 :.O. H CH3

(Complete octet more stable)

AROM ATIC H YDROXY DERIVATIVES

 Phenolic compounds :

Compounds in which —OH group is directly attached to sp2c [Benzene ring]

OH OH OH

CH3 COOH

Phenol o-cresol Salicylic acid

OH OH

OH
OH

OH OH

catechol resorcinol quinol

All phenolic compounds give characteristic colour with neutral FeCl3.

Ph—OH neutralFeCl3 Violet colour

CH3CH2—OH n e utra lF eC l3  No colour

PHENOL (C6H5OH)

Phenol is also known as carbolic acid or Benzenol or hydroxy benzene.In phenol —OH group is attached with
sp2 hybridised carbon.It was discovered by Runge in the middle oil fraction of coaltar distillation and named it
carbolic acid (carbo = coal; oleum = oil) .It is also present in traces in human urine.
 General Methods of preparation :
( 1 ) From benzene sulphonic acid :
When sodium salt of benzene sulphonic acid is fused with NaOH phenol is obtained.

C6H5SO3Na + NaOH    C6H5OH + Na2SO3

( 2 ) From benzene diazonium chloride :
When benzene diazonium chloride solution is warmed, phenol is obtained with evolution of nitrogen.

N2Cl OH
+ N2 + HCl
(Steamdistilled ) H2O

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( 3 ) By distilling a phenolic acid with sodalime (decarboxylation):

OH NaOH CaO OH
COOH + Na2CO3

Salicylic acid
( 4 ) From Grignard reagent : (The Grignard reagent on reaction with oxygen and subsequent hydrolysis by acid

yields phenol)

C6H5MgBr [O] C6H5OMgBr H2O C6H5OH + Mg Br
OH

( 5 ) From benzene :

OH

+ [O] 3V020O5C

( 6 ) From chloro benzene :

Ph—Cl Aq.NaOH No NSR at normal condition

Stable by resonance R —O H [NSR]
Ph—ONa
R—Cl Aq.NaOH

Ph—Cl A q3.0N0aOC H
Order of NSR :

Cl Cl Cl Cl
< NO2
NO2 NO2 NO2

< <

NO2 NO2

max. –I, –M

Aq. NaOH min. ed Aq. NaOH
300°C
min. ESR 25°C
OH max. NSR

OH

NO2 NO2

NO2
2, 4, 6–Trinitrophenol (Picric acid)

( 7 ) Industrial preparation of phenol:
Phenol can be prepared commercially by :
(a) Middle oil fraction of coaltar distillation
(b) Cumene
(c) Raschig process
(d) Dow's process

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( a ) Middle oil fraction of coaltar:

Coaltar Fractional Middle oil (170-230°)

distillation

(Phenol, cresols, Naphthalene)

Coal

Naphthalene liquid
(Solid crystals separate out)
NaOH (dil.)

C6H5ONa

CO2/H2O or sulphuric acid

C6H5OH + Na2CO3

( b ) From cumene (Isopropyl benzene) : Cumene is oxidised with oxygen into cumene hydroperoxide in
presence of a catalyst. This is decomposed by dil. H2SO4 into phenol and acetone.

CH3 CH3 O OH
C(CH3)2
CH OH
+ CH3 C CH3
13O02C HH2SO/ 140,H02CO O

Cumene Cumene hydroperoxide

( c ) Raschig process : Chlorobenzene is formed by the interaction of benzene, HCl and air at 300o C in
presence of catalyst CuCl2 + FeCl3. It is hydrolysed by superheated steam at 425o C to form phenol and

HCl.

1 CuCl2 FeCl3  C6H5Cl + H2O
C6H6 + HCl + 2 O2
3000 C

C6H5Cl + H2O 4250 C C6H5OH + HCl
(super heated steam)

( d ) Dow process : This process involves alkaline hydrolysis of chloro benzene-(large quantities of phenol

formed).

OH

C6H5Cl + NaOH Cu —Fe + NaCl

3000 C

 Physical properties :

(i) Phenol is a colourless, hygroscopic crystalline solid.
(ii) It attains pink colour on exposure to air and light. (slow oxidation)

C6H5OH-------- O O----------- HOC6H5

Phenoquinone(pink colour)
(iii) It is poisonous in nature but acts as antiseptic and disinfectant.

(iv) Phenol is slightly soluble in water , readily soluble in organic solvents.

(v) Solublity of phenol in water is much lower than alcohols because of larger hydrocarbon part in the

molecule.

(vi) Due to intermolecular H-Bonding, phenol has relatively high boiling point than the corresponding

hydrocarbons, aryl halides etc. but intermolecular H-bonding in o–derivatives is used in the preparation

of dyes, drugs, bakelite and it's melting point (MP) is 43° C and boiling point (BP) is 182° C .

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 Chemical Properties :

( A ) Reactions due to –OH group :

 Acidic Nature : Phenol is a weak acid. The acidic nature of phenol due to formation of stable phenoxide
ion in solution. The phenoxide ion is stable due to resonance. The negative charge is spread through out
the benzene ring which is stabilising factor in the phenoxide ion. Electron withdrawing groups
(–NO2, –Cl) increase the acidity of phenol while electron releasing groups (–CH3 etc.) decrease the
acidity of phenol.

C6H5OH    

C6H5 O H3O

Phenol is stronger acid than alcohols but weaker than the carboxylic acids and even carbonic acid

The acidic nature of phenol is observed in the following:

(i) Phenol changes blue litmas to red.

(ii) Highly electro positive metals react with phenol.

2C6H5OH + 2Na  2C6H5ONa + H2

(iii) Phenol reacts with strong alkalies to form phenoxides.

C 6 H 5 OH  NaOH  

C6H5 O N a H2O

(iv) However phenol does not decompose Na2CO3 or NaHCO3 because phenol is weaker than carbonic acid.

C6H5OH + Na2CO3 or NaHCO3  No reaction

P h — O H + NaHCO3 Ph—ONa + H2CO3

Acid-I Base-I Base-II Acid-II

Acid-I < Acid-II Reaction in reverse direction.
Base-I < Base-II

(v) Phenol does not react with NaHCO3.

CH3 C OH + NaHCO3 CH3 C ONa + H2CO3 [H2O + CO2]
O O Acid-II

Acid-I Base-I Base-II

Acid-I > Acid-II Reaction in forward direction.
Base-I > Base-II

(vi) Acetic acid reacts with NaHCO3 and gives effervesence of CO2.

 Reaction with PCl5 : Phenol reacts with PCl5 to form chloro benzene. The yield of chlorobenzene is
poor and mainly triphenyl phosphate is formed.

C6H5OH + PCl5  C6H5Cl + POCl3 + HCl
Ex.
3C6H5OH + POCl3  (C6H5)3PO4 + 3HCl

Reaction with Zn dust: When phenol is distilled with zinc dust benzene is obtained.

C6H5OH + Zn  C6H6 + ZnO

CH2 OH
Zn ?

S o l . No reaction

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CH3 Zn ?
E x . OH

CH3

Sol.

CH3 Zn ?
E x . CH3 Zn ?

S o l . No reaction
COOH

E x . OH

COOH
Sol.

 Reaction with NH3( Bucherer reaction): Phenol reacts with NH3 in presence of anhydrous ZnCl2 to
form aniline.

C6H5OH + NH3 Anhydrous ZnCl2or3(0N0H4C)2SO3 / NH3 150C C6H5NH2 + H2O

 Reaction with FeCl3: Phenol gives violet colouration with FeCl3 solution (neutral) due to formation of a
complex.

C6H5OH + FeCl3  Voilet colour

This reaction is used to differentiate phenol from alcohols.

 Acetylation (Schotten-Baumann reaction) : Phenol reacts with acid chlorides or acid anhydrides in
alkali solution to form phenyl esters.

C6H5OH + ClCOCH3 NaOH C6H5O—C CH3
O
HCl

C6H5OH + Cl C C6H5 NaOH C6H5O C—C6H5
O
HCl

O

 Ether formation (Alkylation) : Phenol reacts with alkyl halides in alkali solution to form phenyl ethers.

(Williamson's synthesis)

C6H5OH + NaOH alkali solution C6H5ONa RNXaX  C6H5OR

Sodium phenoxide

C6H5OH + CH2N2  C6H5OCH3 + N2 

 Reaction with P2S5 : 5C6H5OH + P2S5   5C6H5SH + P2O5

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( B ) Reaction of Benzene Ring : The —OH group is ortho and para directing. It activates the benzene nucleus.
 Halogenation : Phenol reacts with bromine in CCl4 to form mixture of o–and p–bromo phenol.

OH OH OH
+ Br2 CHCl3olorwC. tSe2mopr. CHCl4  Br +

Br
Phenol reacts with bromine water to form a white ppt. of 2,4,6 tribromo phenol.

OH H 2 O OH
+ 3Br2 Br Br

+ 3HBr

Br

 Nitration : Phenol reacts with dil. HNO3 at 0°–10° C to form o- and p- nitro phenols.

OH OH OH
NO2 + NO2 (10%)
d0il.H10NOC3 
(40%)

When phenol is treated with nitrating mixture to form 2,4,6- trinitro phenol (picric acid)

OH NO2 OH
NO2
CCoonncc..HH2NSOO34  [2, 4, 6–Trinitrophenol (Picric acid)]
NO2

 Sulphonation: Phenol reacts with fuming H2SO4 to form o–and p–hydydroxy benzene sulphonic acid
at different temperatures.

OH

25°C SO3H

OH

+ conc. H2SO4 OH

100°C

SO3H

 Friedel-Craft's reaction : Phenol when treated with methyl chloride in presence of anhydrous AlCl3
p-cresol is main product.

OH Anhydrous AlCl3 OH OH
+ CH3Cl CH3 +
CH3
o-cresol p-cresol

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OH OH
OH COCH3 +

+ CH3COCl Anhydrous AlCl3
COCH3

o – and p – hydroxy acetophenone

 Gattermann aldehyde synthesis : When phenol is treated with liquid HCN and HCl gas in presence

of anhydrous AlCl3 yields mainly p- hydroxy benzaldehyde (formylation)

HCl + HCN AlCl3  HN CHCl

OH OH OH
+ HN
CHCl AHlCCll3  HN2HO3 

CH NH CHO

 Riemer-Tiemann reaction : Phenol on refluxing with chloroform and NaOH (aqueous) followed by
acid hydrolysis yields o–hydroxy benzaldehyde. When CCl4 is used salicylic acid is formed.

CHCl3 OH ONa H+  OH
60°C NaOH (aq.) NaOH H2O CHO
CHO
OH CHCl2

Salicylaldehyde

CCl4 OH ONa H+  OH
60°C NaOH (aq.) NaOH COONa H2O COOH

CCl3

Salicylic acid

Mechanism : CCl2 is neutral attacking electrophile (formed by  elimination reaction)
CHCl3 KOH  :CCl2

OH O O O
–HHO2O  
: H Cl
C
CCl2  Cl

OH O 

O

CHO OH  Cl
H  CH
CH OH 
–H2O Cl
OH

 Kolbe 's Schmidt reaction : This involves the reaction of C6H5ONa with CO2 at 1400 C followed by
acid hydrolysis salicylic acid is formed followed.

O Na OCOONa OH OH

140° C Rearrangement COONaH+ COOH

+ CO2 6 atm. pressure H2O

Sodiumphenyl carbonate Sodiumsalicylate Salicylic acid

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 Hydrogenation: Phenol when hydrogenated in presence of Ni at 150-2000C forms cyclohexanol.

OH OH

+ 3H2 Ni 

150 – 200° C

Cyclohexanol. (C6H11OH)
(used as a good solvent)

 Fries rearrangement reaction :

C6H5OH + CH3COCl Anhydrous AlCl3 C6H5OCOCH3

OH

60°C

C6H5OCOCH3 anhydrousAlCl3  COCH3
Phenyl ester (acetate)
OH
COCH3

 Duff 's reaction: This method gives only the o-compound which is hindered by the presence of a –I
group in the ring.

OH OH OH

Glycerol  CH NCH3H2O CHO

+(CH2)6N4 Boric acid

Hexamethylene tetramine acidified with H2SO4
and steam distilled (15–20°C)

 Coupling reactions: Phenol couples with benzene diazonium chloride in presence of an alkaline
solution to form a dye (p- hydroxy azobenzene) red only.

N2Cl + OH NaOH NN OH

–HCl

p–hydroxy azobenzene (Orange dye or Red dye)

Phenol couples with phthalic anhydride in presence of conc. H2SO4 to form a dye (phenolphthalien)
used as an indicator.

O O OH
OH
O C C OH OH H2SO4 O CC
+
H OH –H2O

Phenol (2 molecules) Phenolphthalien (Colourless in acidic
medium and pink in alkaline medium)

 Lederer Manasse (Condensation with formaldehyde) : Phenol condenses with HCHO (excess) in
presence of NaOH or weak acid (H+) to form a polymer known as bakelite (aresin).

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OH OH OH
CH2OH
+ HCHO NaOH
+
CH2OH
(40%) (20%)

Polymerisation
condensation with HCHO

HO CH2 OH

CH2 CH2

OH CH2 OH

CH2 CH2

Polymer bakelite (Phenol formaldehyde resin)

 Leibermann's nitroso reaction : When phenol is reacted with NaNO2 and conc. H2SO4 it gives a
deep green or blue colour which changes to red on dilution with water. When made alkaline with NaOH
original green or blue colour is restrored.
This reaction is used as a test of phenol.

2NaNO2 + H2SO4  2HNO2 + Na2SO4

OH OH O

HONO C6H5OH Green phenolH2O Red NaOH Blue Sodium
H2SO4 or blue colour Salt (original
H NO Indophenol green or blue
colour is restored)
N OH ion

 Reaction with acetone: (Condensation with acetone)

OH OH con. HCl OH OH

HH –H2O CH3 C CH3
O Bis - Phenol-A
p-p'– Isopropylidene diphenol
CH3 C CH3
 Oxidation:

Air [O] O O + H2O p-Benzo quionone (Red)
CrO2Cl2

OH COOH

(O)  H OH
H/KMnO4 Meso tartaric acid

H OH

(Phenol) COOH

K2S2O8/KOH HO OH (Quinol)

(Elb's persulphate reaction)

1, 4 – Dihydroxy benzene

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 Te st of Phenol :
(i) Phenol turns blue litmus to red.
(ii) Aqeous solution of phenol gives a violet colour with a drop of ferric chloride.
(iii) Phenol gives Lieber mann 's nitroso test.
Phenol in conc. H2SO4 exceNssaNofOw2 ater  Red colour NaOHexcess Blue colour
(iv) Aqeous solution of phenol gives a white ppt. of 2,4,6 tribromophenol with bromine water.
(v) Phenol combines with phthalic anhydride in presence of conc. H2SO4 to form phenolphthalein which
gives pink colour with alkali.
(vi) With ammonia and sodium hypochlorite , phenol gives blue colour.

 Differences between phenol and alcohol (C2H5OH) :
(i) Phenol is more acidic than aliphatic alcohol due to resonance in phenoxide ion.
(ii) Phenol gives violet colour with FeCl3 while aliphatic alcohol does not give.
(iii) Phenol gives triphenyl phosphate with PCl5 while aliphatic alcohol gives alkyl chloride.
(iv) Phenol has phenolic odour whereas alcohol has pleasent odour.
(v) Phenol on oxidation gives quinone while alcohol gives aldehyde or ketone and acids.

 Uses of Phenol : Phenol is used :
(a) As an antiseptic in soaps and lotions. "Dettol" (2,4-Dichloro-3,5-dimethyl phenol)
(b) In manufacture of azodyes, phenolphthalein , picric acid (explosive), cyclohexanol (Solvent for rubber),
plastics (bakelite) etc.
(c) In manufacture of drugs like aspirin salol, phenacetin etc.
(d) As preservative for ink.

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ETHER

R—O—R (Dialkyl ether), alkoxy alkane. It's General formula is CnH2n + 2O.
CH3—O—CH2CH3 (Methoxy ethane) or ethyl methyl ether or 2–oxa butane
Ether is monoalkyl derivative of R–OH and dialkyl derivative of H2O

R—OH HR R — O — R 22HR  H—O—H

Classification : They may be classified as :
(a) Simple or symmetrical ether. e.g. R–O–R
(b) Mixed or unsymmetrical ether e.g. R–O–R'
Structure :

: O : sp3 hybridized The molecule of ether is bent due to lone pair of electron on oxygen

bond  110°  bond atom- bond electron repulsion. The bond angle is 1100. It is greater
R R than that of water 1050 due to the repulsion between bulky alkyl groups.

Due to bent structure, it posses dipole moment and hence are polar
molecules.

 General Methods of Preparation :

(A ) From alkyl halides :

(i) By Williamson's synthesis :

R—X + Na—O—R  R—O—R + NaX [ SN2 Reaction]

Example : CH3—I + C2H5 O– Na+  CH3—CH2O—CH3 + NaI
Mechanism : [ SN2 Reaction]

C2H5ONa C2H5O + Na

HH HH

C2H5O C— I Slow C2H5O------ C ----- I Fast C2H5—O—CH3+ I

HH

Na+ I NaI

CH3 CH2

Example : CH3 C Cl + CH3ONa  H3C C

CH3 CH3

CH3   CH3
Example : CH3 C ONa + CH3 CH2 Cl CH3 C O CH2 CH3

CH3 CH3

Example : CH2 CH—Cl + CH3CH2—ONa  No reaction
[Stable by Resonance]

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(ii) Reaction with Dry Ag2O :

2RX + Ag2O   R—O—R + 2AgX

Example : 2CH3—CH2—Cl + Ag2O   CH3CH2OCH2CH3 + 2AgCl
( B ) From R–OH:

(i) By dehydration : R—OH Con. H2SO4  ?

CH3CH2 O 250°C 140°C CH3CH2 O CH2CH3
(Willomson's synthesis)
CH2CH3

Al2O3  CH3 CH2 OHconc.H2SO4

CH2 CH2 350°C 170°C CH2 CH2
(Elimination)

(ii) Reaction with CH2N2 (diazomethane) :

R—OH + CH2—N2 BF3 R—O—CH2—H + N2

 Physical Properties :

(i) CH3OCH3 , CH3OCH2CH3 are gases and higher are volatile liquids.
(ii) Ether are less polar [=1.18D].

(iii) Ethers are less soluble in H2O.
(iv) Ethers have less BP then corresponding alcohol.

Ex. Ethers are less soluble in H2O . Why ?
Sol. Reason : Due to less polar, it forms weaker H–Bonding with H2O.
Ex. Ethers have less BP then corresponding alcohol. Why ?

Sol. Reason : No H–Bonding in ether molecules.

 Chemical properties :

Ethers are less polar so less reactive and do not react with active metals [Na,K], cold dil. acid, oxidising and
reducing agent.

Reason : They do not have any active functional group.

1 . Basic nature : Due to presence of .p on oxygen atom ether behave as lewis base

Ethers react with cold conc. acid and form oxonium ion

Example : .. cold; conc. HCl C2H5  C2H5 Cl (diethyl oxonium chloride)
C2H5.O. C2H5
O

H

Example : C2H5 .. C2H5 cold; conc. C2H5  C2H5 HSO4 (diethyl oxonium hydrogen sulphate)
O..
H2SO4 O

H

Ether form dative bond with Lewis acids like BF3, AlCl3, RMgX etc.

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Example : R O..: F R .. R
BF O..

RF R Mg X [Ether is used as solvent] for Grignard reagent.

..
O..
RR

2 . Halogenation :

CH3CH2 O CH2CH3 Cl2/dark CH3CH O CH CH3

Cl Cl
'–Dichloro diethyl ether

10 Cl2 light C2Cl5 O C2Cl5 + 10 HCl
Perchlorodiethyl ether

3 . Formation of peroxides : Ether add up atmospheric oxygen or ozonised oxygen. It is explained by Free
radical mechanism as intermediates is free radical.

C 2 H 5 — O — C 2 H 5 OL2on(ngocnopnotalacrt) CH3CH2 O CHCH3

(Non polar) sunlight or UV O OH

.. .. ..
C2H5.O. C2H5 + O..  C2H5O..C2H5 or (C2H5)2O O

..
:O..:

CH3CH2—O—CH2—Ph long Oco2ntact  CH3—CH2—O—  —Ph O2  CH3 CH2 O CH Ph
O OH
CH

stable by resonance

Peroxides are unstable and explosives.

Test for peroxides

ether (peroxide) FeSO4/ KCNS Red colour

ether (Peroxides) + Fe+ 2  Fe+ 3 CNS  Fe(CNS)3
(R ed)

4 . Reaction with hot dil. H2SO4 : R — O — R Hho2St Odi4l 2 R — O H

5 . Reaction with hot conc. H2SO4 : R — O — R hotconc.H2SO4  2RHSO4

CH3 CH2 O CH2 CH3 H2SO4 cold dil.

No Reaction
Oxonium salt

cold conc.

hot dil. Ethyl alcohol
hot conc. Ethyl hydrogen sulphate

6 . Reaction with PCl5 : ROR + PCl5 heat  2RCl + POCl3
7 . Reaction with BCl3 : 3ROR + BCl3  3RCl + (RO)3B

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8. Reaction with RCOCl : ROR + RCOCl AlCl3  RCOOR +RCl

ZnCl2 heat

9 . Reaction with CO : ROR + CO BF3/ H15gO05C00 atm  RCOOR



1 0 . Reaction with C2H 5Na : CH2CH2 O CH2CH2 + C2H5  CH3CH2OH + CH2 CH2+C2H6
H H Stronger

base

11 . Dehydration : CH3CH2 O CH2CH3 Al2O3  2CH2 CH2 + H2O

12 . Reduction : CH3CH2OCH2CH3 Re dhePat HI 2CH3CH3

13 . Oxidation :

CH3CH2—O—CH2CH3 H / K2Cr2O7  2CH3CH2OH [O] 2CH3CHO [O] 2CH3COOH

14 . Combustion : C2H5OC2H5 + 6O2  4CO2 + 5H2O
(explosive mixture)

1 5 . Reaction with HX : Reactivity of HX HI > HBr > HCl

 Reaction with cold conc. HX :

Ethers forms oxonium salt with cold and conc. HCl (less reactive)
Cold conc. HI and HBr (more reactive) break C–O bond.

CH3
E x . CH3 C O CH2 CH3 Cold aHndI conc.  ?

CH3

Sol. Mechanism

CH3 CH3 CH3

CH3 C .. H+ CH3 C O CH2CH3  CH3 
.O. CH2CH3

CH3 CH3 H CH3
(Oxonium ion) I

CH3

CH3 C I + CH3CH2OH

CH3

 

 If oxonium ion gives more stable carbocation [ Ph CH2, CH2 CH— C H2, (CH3)3 C ] then SN1 reaction occurs.

 

 If oxonium ion gives less stable carbocation [P h , CH2 C H, CH3 C H2] then SN2 reaction occurs,

and X attacks at less hindered carbon.

E x . CH3CH2—O—CH2Ph ColHd cIon. CH3CH2—OH + PhCH2—I, write mechanism of given reaction.

Sol. Mechanism :

.. H   I  PhCH2I
CH3CH2O..CH2Ph CH3CH2OH + CH3CH2–OH
CH3CH2 O CH2Ph + Ph CH2

H

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E x . CH3CH2—O—CH3 anhy.HI  ?

.. HI  I CH3I + CH3CH2OH
S o l . CH3CH2 O.. CH3
CH3CH2 O CH3

H

Oxonium ion gives less stable carbocation

SN2 reaction I attacks at less hinderd carbon.

E x . CH3—CH2—O—Ph (aq.)HBr ?

Sol. Mechanism : CH3 CH2 .. Ph H+ CH3 CH2  PhBrCH3CH2Br + PhOH
O..
O

H

SN1 2°

CH3CH2OH + I CH CH3

CH3CH2 O CH CH3 coldanIdconc.HI CH3
CH3
SN2 CH3CH2 I + HO CH CH3

1°

CH3

 If excess of HI is used then two moles of alkyl hallides are formed.

 CH3CH2—O—CH2Ph HI CH3CH2OH+PhCH2I HI CH 3CH2 — I  PhCH2 — I
( B ) Reaction with hot and conc. HX :

CH3CH2—O—CH3 hotand concHI CH3CH2—I + CH3—I

E x . C2H5—O—C2H5 hotandconc.HBr ? + ?

S o l. C2H5—Br + C2H5 — Br

 Uses of ether :

(i) General anaesthetics agent.
(ii) Refrigerant a mixture of ether and dry ice gives temperature as low 110°C.
(iii) Solvent for oil, fats, resins, Grignard reagent.
(iv) For providing inert & moist free medium to organic reaction example : Wurtz reactions.
(v) In perfumery.
(vi) Di-isopropyl ether  Petrol as an antiknock comp.
(vii) Mixture of alcohol and ether is used as a substitute of petrol. Trade name "Natalite"
(viii) Halothane (CF3CHClBr) used as an anaesthetic because it produces unconsciousness without affecting

lung and heat.
 Preparation of Epoxides :

(i) Epoxidation of alkenes by reaction with peroxy acids
(ii) Base-promoted ring closure of vicinal halohydrins
(iii) Epoxidation of alkenes by reaction with peroxy acids

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 Epoxidation of alkenes by reaction with peroxy acids :

OO

C=C + R–C–OOH C—C + R–C–OH

Peroxy acid O
Epoxide

Example :

O O
(a) CH2= CH–(CH2)9–CH3 + CH3–C–COOH CH2–CH(CH2)9CH3 + CH3–C–OH

O O
(b) + CH3–C–OOH O

O + CH3–C–OH

(c) Epoxidation is a stereospecific syn addition :

C6H5 H O C6H5 H O
C= C + CH3–C–OOH
+ CH3–C–OH
H C6H5 H O C6H5

(E) -1,2-diphenyl ethene trans -2,3-diphenyl oxirane

Mechanism :

H C OC O
O C

CH3–C O CH3–C O CH3–C H + O––C––

O OC OC

transition state Epoxide

 Base-promoted ring closure of vicinal halohydrins :

R C = CR x2  HO– R2C–––CR2
22 H2o R2C––CR2 O

HO X Epoxide
Vicinal halohydrin

Mechanism : RX RX
Step I R C––C R + HO—H
R C––C R
–O.. R
.... O..R
..HO..– H
..
..

..
..

..

..
..
Step II RX RR ..
R C––C R R C––C R + X– ..

–O.. R O

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Example :

HH
OH

NaOH

O
(i)

OH
Br H
trans-2-bromocyclohexanol 1, 2-epoxycyclohexane

H3C Br
H3C
H
H3C H H
Br2/H2O
inversion of
configuration H3C
(ii) H3C Anti addition H H

H H3C OH O

cis-2-butane cis-2, 3-epoxybutane

H Br H

CH3 H CH3 inversion of CH3
H
(iii) H3C Br2/H2O configuration H3C
Anti addition
H
H H3C
OH O
trans-2-butane
trans-2, 3-epoxybutane

 Reaction of Epoxides :
 With Grignard reagent :

RMgX + H2C––CH2 (1)(d2ie) tHh3yOlether  RCH CH OH (primary alcohol)
O 22

CH2MgCl + H2C––CH2 (i) diethylether CH2CH2CH2OH
(ii) H3O+ 3-phenyl-1-propanol
Benzyl magnesium O
chloride
Ethylene
oxide

 Nucleophilic ring opening reactions of epoxides :

YY

Y:– + R2C––––CR2 R2C–––CR2 H2O R2C–––CR2
O O.. O..H
..
..

..
..

H2C–––CH2 KS CH2 CH2CH3 CH3––CH2CH2––CH2SCH2CH2OH
O ethanol water, 0C

2-(butylthio) ethanol

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Note : Nucleophilic ring opening reactions of epoxides is the characteristic feature of SN2 reaction.

H OCH2CH3

(i) H NaOCH2CH3  H
CH3CH2OH H

O

OH

H3C CH3

H OH

H NH3/H2O
H3C
O H2N H
H

CH3

H3C CH3 CH3O CH3

(ii) C––––C NaOCH3  CH3––CH––C––CH3
CH3OH

H O CH3 OH

 Nucleophilic ring opening of epoxides :

C H MgBr + H2C–––CHCH3 1, diethyl ether  C6H5CH2CH––CH3
65 2, H3O

O OH

R R R R
..
–Y: O....–.. O..H
O Y
– O....– Y
Y
-substituted alcohol
epoxide transition state alkoxide

CH2–––CH(CH2)7CH3 1. LiAlH4  CH3––CH––(CH2)7CH3
O 2, H2O OH

(i) H2C–––CH2 HBr BrCH CH OH
10C 22

O

(ii) H2C–––CH2 CH3CH2OH CH –CH OCH CH OH
H2SO4 , 25C 32 22

O

H2C–––CH2 + HO H3O  HOCH CH OH
2 22

O

Mechanism

Step-1 : + H ..
H H2C–––CH2 + H2O:
H2C–––CH2 + H—O:
:O: :O+

H

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H H2C–.–.–CH2 Slow +H
:O: + O+
H—.O. ..
Step-2 : H ....CH2–CH2–O–H

..H
..
Step-3 : + H H O—+ H .. ..

H—O .. + HO..CH2CH2.O.H
H
..CH2–CH2–O–H
:O: +
H
H

H

Example : H OH

O HBr

H OH
1,2-Epoxycyclohexane H
trans -2-bromo cyclohexanol

H3C CH3 OCH3
CH3––CH––C––CH3
C–––C CH3OH
H2SO4 HO CH3
3-methoxy-3-methyl-2-butanol
H O CH3

2,2,3-trimethyl oxirane

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