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Functional Group
Alcohol
Organic Name :
Group 1 :Abdurrohman Dzaky Al Hafidz
M. Andika AryanaReky Hermawan
Saptio AjiSuhartini Lestari Putri
Definition
Classification
Properties
PhysicalProperties
ChemicalProperties
Alcohols
Important Individual Alcohol
Nomenclature
Preparation
Definition
• Alcohol are compounds in wich a hydroxyl group (-OH) is attached to a saturated carbon
• The general formula of alcohol is ROH (R= alkyl, substitution alkyl, or syclic hidrokarbon)
Example: CH3-OH (metanol)
CH3CH-OH (etanol)
Alcohols
Nomenclature of Alcohols
• IUPAC SystemStep 1 : Name the longest chain to which the hydroxyl group is attached. (alkane –e + ol = Alkanol)Step 2 : Number the longest chain to give the lowest number to the carbon attached to the hydroxyl groupStep 3: Indicate the position of the hydroxyl group by the number of the carbon atom to which is attachedStep 4: Indicate the position of other substitutients or multiple bonds by number
Alcohols
Nomenclature of Alcohols
• IUPAC SystemExample:
3 2 1
CH3CH2CH2OH 1-propanol 1 2 3
CH3CH2CH2 2-propanol
OH
Alcohols
Classification of Alcohols
Monohydric alcohols are classified as primary (1o), secondary (2o), or tertiary (3o) :
• In primary (1o) alcohols the –OH is attached to a C atom which is attached to one other
• In secondary (2o) alcohols the –OH is attached to a C atom which is attached to two other
• In tertiary (3o) alcohols the –OH is attached to a C atom which is attached to three other
Alcohols
Classification of Alcohols
Example:primary (1o) : R-CH2-OH
CH3-CH2-CH2-OH 1-propanol (n-propyl alcohol)
secondary (2o):
R-CH-OH R’
CH3-CH-OH 2-propanol (isopropyl alcohol)
CH3
Alcohols
Classification of Alcohols
Example:tertiary (3o) :
CH3
CH3-CH-OH 2-methyl-2-propanol (t-buthyl alcohol)
CH3
R’’R-CH-OH R’
Alcohols
Physical Properties of Alcohols
• Boiling PointsAlcohol have hinger boiling points than alkanes of similar molecular weight. Alcohol boiling points increase as carbon-chain length increases.Example:CH3-OH methyl alcohol BM= 32 oC= 65
CH3-CH2-OH ethyl alcohol BM= 46 oC= 78CH3-CH2-CH2-OH n-propyl alcohol BM= 60 oC= 97
Alcohols
Physical Properties of Alcohols
• SolubilityThe polar part of the alcohol molecule increases solubility in water, but the non polar part decrease solubility.Size of the non polar alkyl group is large the solubility of alcohol in water decrease dramatically
Alcohols
1. Reaction with active metalsAlkoxides are formed by Na, Mg, Al etc
H3C-CH2-OH H3C-CH2-ONa Sodium ethoxide
Na
Chemical Properties of Alcohols
Alcohols
2. Ester Formation OH3C-CH2-OH + H3C-CH2-C-OH
ethanol propanoic acid
OH3C-CH2-C-O-CH2-CH3 + H2O
diethyl ester
Alcohols
Alcohols
3. Dehydration (Reaction with sulphuric acid)a. Alkene Formation
Conc. H2SO4 OH
H3C-CH2-CH-CH3
H3C-CH2-CH=CH2
1-butene
Minor Product
H3C-CH=CH-CH3
2-butene
Major Product
+
Alcohols
3. Dehydration (Reaction with sulphuric acid)b. Ether Formation
Conc. H2SO4 2 H3C-CH2-OHethanol
H3C-CH2-O-CH2-CH3
diethyl etherH2O+
140o
Alcohols
3. Dehydration (Reaction with sulphuric acid)c. Alkyl hydrogen sulphates formation
roomH3C-CH2-OHethanol
H3C-CH2-O-SO2OH Ethyl hydrogen sulphate
H2O
+temperature
HO-SO2OH
+
Alcohols
4. Alkyl halides formation (R-X)a. Reaction with thionyl chloride (SOCl2)
H3C-CH2-OHethanol
H3C-CH2-Cl Ethyl chloride
SO2+ SOCl2+ + HCl
Alcohols
4. Alkyl halides formation (R-X)b. Reaction with phosphorus halides (PX3 or PX5)
H3C-CH2-OHethanol
H3C-CH2-Cl Ethyl chloride
POCl3+ PCl5+ + HCl
3 H3C-CH2-OHethanol
+ PCl3
H3C-CH2-Cl Ethyl chloride
+ H3PO3
Alcohols
5. Reaction with hydrogen halides (HX)HCl react with alcohols only in the presence of catalyst (anhydrous ZnCl2). No catalyst is required in the case of HBr or HI
H3C-CH2-OHethanol
+ HBr + H2OH3C-CH2-Br Ethyl bromide
Alcohols
6. Reaction withnitric acid (HNO3)alkyl nitrates are formedH3C-CH2-OH + HBr H3C-CH2-O-NO2 + H2O
ethanol ethylnitrate
7. Oxydation Different types of alcohols give different products on
oxidation. Most widely used oxidizing agents are KMnO4 + H2SO4 and Na2Cr2O7 + H2SO4
Alcohols
a) Primary alcohols are oxidized to aldehydes, which are, in turn, easily axidized to carboxilic acids. The reaction can be stoped at the aldehyde stage, by removing them from the oxidizing medium as they are farmed (e.g. Destilation)
OO
H3C-CH2-OH + H3C-C-H H3C-C-OH
Ethylalcohol acetaldehyde aceticacid
Alcohols
b.) secondary alcohol are oxidazed to ketones O O
H3C-CH-CH3 + H3C-C-CH3 + H2OIsoprophyl alcohol acetone
c.) Tertiary alcohol don’t undergo oxidation under normal condition. OH
H3C-C-CH3 + NO REACTION (NR)
CH3
Tert-buthyl alcohol
Alcohols
8. Reaction with hot copper ( catalytic dehydrogenation)
Different types of alcohols give different products when their vapours are passed over copper gauze at 3000C
a) Primary alcohols give aldehydes + hydrogen O
H3C-CH2-OH H3C-C-H + H2
Ethylalcohol Acetaldehyde
Alcohols
b. ) Secondary alcohols give ketone + hydrogen OH O
H3C-C-CH3 H3C-C-CH3 + H2Isoprophyl alcohol Acetone
c. ) Tertiary alcohols give alkenes + water OH CH2
H3C-C-CH3 H3C-C + H2O
CH3 CH3Tert-butyl alcohol 2-methyl propene
Preparation of Alcohols
1. Hydrolysis of Alkyl halides with aqueous NaOH
Keduanya akan berikatan menjadi NaBrH2C CH2 OHH3C
propanol
Bagian OHnya akan pindah
H2C CH2 BrH3C
1-bromopropane
NaOH 𝐻2𝑂→
Alcohols
CH2 CH
OSO3H
CH3
sec-butyl hydrogen sulfate
H3C
H2C CH CH2H3C
butene
HOSO3H
Sesuai hukum Markovnikov maka bagian positifnya akan menuju ke bagian C yang Hnya paling banyak
H2C CH CH2H3C
butene
HOSO3H
2. Hydration of AlkenesAlkenes react with conc. H2SO4 to form alkyl hydrogen sulphates which on hydrolysis yield alcohols
Alcohols
CH2 CH
OSO3H
CH3
sec-butyl hydrogen sulfate
H3C
H
O H
CH2 CH
OH
CH3
butanol
H3C H2SO4
Keduanya akan berikatan menjadi H2SO4
Bagian OHnya pindah karena bagian OSO3 yang bermuatan negatif sudah berikatan dengan H
CH2 CH
OSO3H
CH3
sec-butyl hydrogen sulfate
H3C
H
O H
Alcohols
C
OMgX
R
addition
3. Addition of Reagents to aldehydes and ketones
C
O
aldehyde
R MgX
Grignard
Ikatan double bond putus. Bagian R akan pindah ke C. Bagian MgX akan pindah ke O
𝐻2𝑂→H+
OMgX akan menjadi OH saat bereaksiC
OH
R
alcohol
MgX(OH)
Alcohols
H C H
O
R MgXH C H
OMgX
R
𝐻2𝑂→H+
• Primary AlcoholsObtained by treating Grignard reagents with formaldehyde
H C H
OH
R
MgX(OH)
Ikatan double bond putus. Bagian R akan pindah ke C. Bagian MgX akan pindah ke O
OMgX akan menjadi OH saat bereaksi
Alcohols
𝐻2𝑂→H+
• Secondary AlcoholsObtained by treating Grignard reagents with other aldehyde
MgX(OH)
Ikatan double bond putus. Bagian R akan pindah ke C. Bagian MgX akan pindah ke O
OMgX akan menjadi OH saat bereaksi
R MgXCH3 C H
O
H3C C H
OMgX
R
H3C C H
OH
R
Alcohols
𝐻2𝑂→H+
• Tertiary AlcoholsObtained by treating Grignard reagents with ketones
MgX(OH)
Ikatan double bond putus. Bagian R akan pindah ke C. Bagian MgX akan pindah ke O
OMgX akan menjadi OH saat bereaksi
R MgXCH3 C CH3
O
H3C C CH3
OMgX
R
H3C C CH3
OH
R
Alcohols
4. Reduction of aldehydes and ketones with H2/Ni or lithium aluminium hydride (LiAlH4)
Aldehydes give primary alcoholsKetones give secondary alcohols
H3C CH2 OH
ethyl alcohol (1o)
Alcohols
H3C C H
O
acetaldehyde
𝑁 𝑖→
Ikatan rangkap putus O pindah ke H menjadi OHH akan berikatan dengan C
H3C CH
OH
CH3
isopropyl alcohol (2o)
Alcohols
H3C C CH3
O
acetone
𝐿𝑖𝐴𝑙𝐻 4→
Setelah bereaksi ikatan double bond hilang dan O menjadi OH
5. Reduction of acids with lithium aluminium hydride (LiAlH4)
H3C CH2 CH2 C
O
OH
butyric acid
H3C CH2 CH2 CH2 OH
butan-1-ol
𝐿𝑖𝐴𝑙𝐻 4→
Setelah bereaksi ikatan double bond dan O hilang
Alcohols
6. Acid-hydrolysis of esters
C3H7OH
propan-1-ol
H3C C
O
OH
acetic acid
H3C C
O
OC3H7
propyl acetate
H
O H
Keduanya akan bereaksi menjadi C3H7OHOH akan pindah sehingga akan membentuk asam asetat
Alcohols
Important Individual Alcohols
• Methanol (methyl alcohol, wood alcohol). In industry, it is used as the raw material for making formaldehyde, as a solvent, and as a denaturant.
• Ethanol (ethyl alcohol, grain alcohol). In industry ethanol is used as a solvent and to prepare perfumes, lotions, and rubbing compound.
• 2-propanol (isopropyl alcohol) otu used as a disinfectant
Alcohols
Important Individual Alcohols
• 1,2-ethanediol (ethylene glycol) and 1,2- propanediol (propylenglycol) are components in permanent type antifreezes.
• 1,2,3-propanetriol (glycerol, glycerin) it used as afood additive to help keep food moist
• Sugars. All carbohydrates consist of polyhydroxy compounds
Alcohols
Thank You