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Lisa Andina, S. Farm., Apt.
Alcohols
• Classification Primary: carbon with –OH is bonded to one other carbon.
Secondary: carbon with –OH is bonded to two other carbons.
Tertiary: carbon with –OH is bonded to three other carbons
Aromatic (phenol): -OH is bonded to a benzene ring
Classify these:
CH3 CH
CH3
CH2OH CH3 C
CH3
CH3
OH
OH
CH3 CH
OH
CH2CH3
IUPAC Nomenclature
• Find the longest carbon chain containing the carbon with the -OH group.
• Drop the -e from the alkane name, add -ol.• Number the chain, starting from the end
closest to the -OH group.• Number and name all substituents.
Name this:
CH3 CH
CH3
CH2OH
CH3 C
CH3
CH3
OH
CH3 CH
OH
CH2CH3
OH
Br CH3
Hydroxy Substituent
• When -OH is part of a higher priority class of compound, it is named as hydroxy.
• Example:
CH2CH2CH2COOH
OH
4-hydroxybutanoic acid
Naming Diols
• Two numbers are needed to locate the two -OH groups.
• Use -diol as suffix instead of -ol.
HO OH
Physical Properties
• Unusually high boiling points due to hydrogen bonding between molecules.
• Small alcohols are miscible in water, but solubility decreases as the size of the alkyl group increases
Boiling Points
Solubility decreases as the size of the alkyl group increases.
=>
Acidity of Alcohols
• pKa range: 15.5-18.0 (water: 15.7)
• Acidity decreases as alkyl group increases.• Halogens increase the acidity.• Phenol is 100 million times more acidic than
cyclohexanol!
Pembuatan• Reduction of
Aldehydes/Ketones–Hydrogenation
R CO
H RCH2OHH2
Pt Primary ROH
R CO
R'H2Pt
R COH
HR' Secondary ROH
–Hydride Reductions R C
OH
LiAlH4
R CO
R'LiAlH4 R C
OH
HR' Secondary ROH
orNaBH4
or NaBH4
RCH2OH Primary ROH
•Reduction of Carboxylic Acids and Esters
–Lithium Aluminum Hydride Reduction
•Acid-Catalyzed Hydration of Alkenes R C C H
H HH+
H2OR C C
H
H
H
H
OH
R C C
HR'
R''H+
H2OR C C
H
HOH
R'
R''
• Hydration of Alkenes via Oxymercuration/Demercuration
R C C H
H H
H2OR C C
H
H
H
H
OH
R C C
HR'
R'' R C C
H
HOH
R'
R''
Hg(OAc)2 NaBH4
H2O
Hg(OAc)2 NaBH4
•Hydroboration-Oxidation of Alkenes R C C H
H H
R C C
H
H
H
H OH
R C C
HR'
R'' R C C
HR'
R''
H OH
(BH3)2 OH-
H2O2
(BH3)2 OH-
H2O2
•Grignard Additions to Aldehydes/Ketones H C H
O
RMgXRCH2OH Primary ROH
RMgX
RMgX
R' C
OH
H
RR'
O
HC
R' R"
O
C R' C
OH
R
R"
Secondary ROH
Tertiary ROH
•Grignard Additions to Esters H C
O
OR R'MgX+ 2 R'2CHOH +ROHSecondary ROH
R'MgX+ 2R" C
O
OR R" C
R'
R'
OH +ROH
Teriary ROH
•Typical Alcohol Reactions
• Reaction with Active Metals
ROHNa
RO- Na++H2
• Hydrogen Halide Conversion of Alcohols to Alkyl Halides RCH2OH HX RCH2X
SN1
SN2 predominantly
predominantly
SN1 SN2orHX
HX
R2CHOH R2CHX
R3COH R3CX
where HX = HI, HBr, or HCl
• Haloform Reaction CH3 C
OH
H
HX2
OH-H+
H C
O
OHHCX3 +
CH3 C
OH
H
RX2
OH-H+
HCX3 + C
O
OHR
Phenols Ar-OH
• Phenols are compounds with an –OH group attached to an aromatic carbon. Although they share the same functional group with alcohols, where the –OH group is attached to an aliphatic carbon, the chemistry of phenols is very different from that of alcohols.
Nomenclature.
Phenols are usually named as substituted phenols. The methylphenols are given the special name, cresols. Some other phenols are named as
hydroxy compounds. OH
phenol
OH
Br
m-bromophenol
CH3
OH
o-cresol
OH
COOH
salicylic acid
OH
OH
OH
OH
OH
OH
catechol resorcinol hydroquinone
COOH
OH
p-hydroxybenzoic acid
physical properties
• phenols are polar and can hydrogen bond• phenols are water insoluble• phenols are stronger acids than water and will
dissolve in 5% NaOH• phenols are weaker acids than carbonic acid
and do not dissolve in 5% NaHCO3
phenols, syntheses:
• 1. From diazonium salts
• 2. Alkali fusion of sulfonates
N2
H2O,H+
OH
SO3 Na NaOH,H2O
300o
ONaH+ OH
Hydrolysis of Chlorobenzene (Dow Process)– Chlorobenzene is heated with sodium hydroxide under
high pressure
From Cumene Hydroperoxide
• Benzene and propene are the starting materials for a three-step sequence that produces phenol and acetone
• Most industrially synthesized phenol is made by this method
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