This document discusses the classification, nomenclature, physical properties, synthesis, and reactions of alcohols. Alcohols are classified based on the carbon chain containing the hydroxyl group as primary, secondary, or tertiary. They can be synthesized by hydrolysis of alkyl halides, fermentation of sugars, or oxidation of aldehydes or alkenes. Common reactions include forming esters, undergoing halogenation with HX, and being oxidized to carbonyl compounds.

1. Alcohols R-O-H
Classification CH3, 1o, 2o, 3o
Nomenclature:
Common names: “alkyl alcohol”
IUPAC: parent = longest continuous carbon chain
containing the –OH group.
alkane drop -e, add –ol
prefix locant for –OH (lower number for OH)

2. CH3 CH3
CH3CHCH2CHCH3 CH3CCH3
OH OH
4-methyl-2-pentanol tert-butyl alcohol
2-methyl-2-propanol
2o 3o
CH3
HO-CHCH2CH3 CH3CH2CH2-OH
sec-butyl alcohol n-propyl alcohol
2-butanol 1-propanol
2o 1o

3. Physical properties of alcohols:
polar + hydrogen bonding
relatively higher mp/bp
water insoluble!
(except for alcohols of three carbons or less)
CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2-OH
hydrophobic hydrophilic

4. Oldest known organic synthesis:
“fermentation”
Sugar + yeast  ethyl alcohol + CO2
Grape juice => “wine”
Barley => “beer”
Honey => “mead”
Rice => “sake”
~5-11% ethanol

5. Distillation of fermented beverages to produce “distilled spirits”
with a greater percentage of ethyl alcohol (bp 78.3 oC).
Ethyl alcohol forms a binary azeotrope with water:
95% ethanol + 5% water (bp 78.15oC)
Diluted with water => “vodka” 40% ethyl alcohol in water.
“proof”: when aqueous alcohol is placed on a sample of
gunpowder and ignited, the gunpowder will burn at a minimum
concentration of 50% alcohol. This is called “100-proof”.
(proof = 2 * alcohol percent)

6. Add oil of juniper => gin
Add peat smoke => scotch
Age in a burned barrel => whiskey
Add peppermint => schnapps
Etc.
Ethyl alcohol is a poison. LD50 = ~10g/Kg orally in mice.
Nausea, vomiting, flushing, mental excitement or depression,
drowsiness, impaired perception, loss of coordination, stupor,
coma, death may occur. (intoxication)

7. Alcohols, synthesis:
1.
2.
3.
4. Hydrolysis of alkyl halides (CH3 or 1o)
5.
6.
7.
8.

8. R-H R-X R-OH
NR NR 
NR  some
NR  
NR NR 1o/2o
NR  NR
NR NR NR
Acids
Bases
Active
metals
Oxidation
Reduction
Halogens

9. Alcohols, reactions:
R-|-OH
1. With HX
2. With PX3
3. (later)
RO-|-H
4. As acids
5. Ester formation
6. Oxidation

10. 1. Reaction of alcohols with HX: (#1 synthesis of RX)
R-OH + HX  R-X + H2O
a) HX: HI > HBr > HCl
b) ROH: 3o > 2o > CH3 > 1o
c) May be acid catalyzed
d) Rearrangements are possible except with most 1o alcohols.

11. CH3CH2CH2CH2-OH + NaBr, H2SO4, heat  CH3CH2CH2CH2-Br
n-butyl alcohol n-butyl bromide
1-butanol 1-bromobutane
CH3 CH3
CH3C-OH + HCl  CH3C-Cl (room temperature)
CH3 CH3
tert-butyl alcohol tert-butyl chloride
2-methyl-2-propanol 2-chloro-2-methylpropane
CH3CH2-OH + HI, H+, heat  CH3CH2-I
ethyl alcohol ethyl iodide
ethanol iodoethane

12. Mechanism?
CH3-OH and most 1o alcohols react with HX via SN2 mechanism
3o and 2o react with HX via SN1 mechanism
Both mechanisms include an additional, first step, protonation
of the alcohol oxygen:
R-OH + H+  R-OH+ “oxonium ion”
2

13. Whenever an oxygen containing
compound is placed into an acidic
solution, the oxygen will be
protonated, forming an oxonium ion.

14. Mechanism for reaction of an alcohol with HX:
CH3OH or 1o alcohols:
SN2
1) R-OH + HX R-OH2 + X
RDS
2) X + R-OH2 R-X + H2O

15. Mechanism for reaction of an alcohol with HX:
2o or 3o alcohols:
SN1
1) R-OH + HX R-OH2 + X
RDS
2) R-OH2 R + H2O
3) R + X R-X

16. May be catalyzed by acid.
SN2 rate = k [ ROH2
+ ] [ X- ]
SN1 rate = k [ ROH2
+ ]
Acid protonates the -OH, converting it into a better leaving
group (H2O), increasing the concentration of the oxonium ion,
and increasing the rate of the reaction.

17. Rearrangements are possible (except with most 1o alcohols):
CH3 CH3
CH3CHCHCH3 + HBr  CH3CCH2CH3
OH Br
 ­ Br-
CH3 CH3 [1,2-H] CH3
CH3CHCHCH3  CH3CHCHCH3  CH3CCH2CH3
OH2+ + +
2o carbocation 3o carbocation

18. In the reaction of most 1o alcohols with HX you don't have
to worry about the possibility of rearrangements. The mechanism
is SN2 and does not involve carbocations.
CH3CH2CH2CH2CH2-OH + HBr, H+, heat
CH3CH2CH2CH2CH2-Br
1-pentanol
1o alcohol:
No rearrangement, SN2
1-bromopentane

19. Most 1o? If large steric requirement…
CH3 CH3
CH3CCH2-OH + HBr  CH3CCH2CH3
CH3 Br
neopentyl alcohol 2-bromo-2-methylbutane
 
CH3 CH3 CH3
CH3CCH2-OH2
+  CH3CCH2+  CH3CCH2CH3
CH3 CH3 +
1o carbocation 3o carbocation
[1,2-CH3]

20. 2. With PX3
ROH + PX3  RX
a) PX3 = PCl3, PBr3, P + I2
b) No rearrangements
c) ROH: CH3 > 1o > 2o

CH3 CH3
CH3CCH2-OH + PBr3  CH3CCH2-Br
CH3 CH3
neopentyl alcohol 2,2-dimethyl-1-bromopropane

21. 3. Dehydration
(later)

22. 4) As acids.
a) With active metals:
ROH + Na  RONa + ½ H2 
b) With bases:
ROH + NaOH  NR!
CH4 < NH3 < ROH < H2O < HF

23. CH3CH2OH + NaOH  H2O + CH3CH2ONa
WA WB SA SB
CH3CH2OH + CH3MgBr  CH4 + MgBr(OCH2CH3)
SA SB WA WB
CH3OH + NaNH2  NH3 + CH3ONa
SA SB WA WB

24. 5. Ester formation.
CH3CH2-OH + CH3CO2H, H+  CH3CO2CH2CH3 + H2O
CH3CH2-OH + CH3COCl  CH3CO2CH2CH3 + HCl
CH3-OH + CH3SO2Cl  CH3SO3CH3 + HCl
Esters are alkyl “salts” of acids.

25. O
R C
OH
O
R C
ONa
O
R C
OR'
carboxylic acid sodium salt ester
O
R S
O
O
OH R S
O
O
OK R S
O
OR'
sulfonic acid potassium salt ester
O
HO P
OH HO P
OH
O
OR HO P
OH
O
OR RO P
OR
O
OR
OR
phosphoric acid monoester diester triester

26. "Lasso" chemistry
O
R C
O H
O
R C
O R'
H-O-R'
H+
+ + H2O
O
O H
CH3C
CH3 H+
+ H-O CHCH3
O
O CHCH3
CH3C
CH3 + H2O
acetic acid isopropyl alcohol isopropyl acetate

27. acid chloride + alcohol --> ester
O
R C
Cl
O
R C
O R'
H-O-R'
H+
+ + HCl
O
Cl
CH3C
CH3 H+
+ H-O CHCH3
O
O CHCH3
CH3C
CH3 + HCl
acetyl chloride isopropyl alcohol isopropyl acetate

28. O
R S
O
Cl
sulfonyl chloride
O
+ H-O-R R S
O
O-R + HCl
alcohol sulfonate ester

29. oxidation states of carbon
- oxidation 
CH4 CH3OH CH2O HCO2H CO2
-4 -2 0 +2 +4
 reduction -

30. 6. Oxidation
Oxidizing agents: KMnO4, K2Cr2O7, CrO3, NaOCl, etc.
Primary alcohols:
CH3CH2CH2-OH + KMnO4, etc.  CH3CH2CO2H
carboxylic acid
Secondary alcohols:
OH O
CH3CH2CHCH3 + K2Cr2O7, etc.  CH3CH2CCH3
ketone
Teriary alcohols:
no reaction.

31. Primary alcohols can also be oxidized to aldehydes:
CH3CH2CH2-OH + C5H5NHCrO3Cl  CH3CH2CHO
pyridinium chlorochromate aldehyde
or
CH3CH2CH2-OH + K2Cr2O7, special conditions 

32. Alcohols, synthesis:
1.
2.
3.
4. Hydrolysis of alkyl halides (CH3 or 1o)
5.
6.
7.
8.

33. Alcohols, reactions:
R-|-OH
1. With HX
2. With PX3
3. (later)
RO-|-H
4. As acids
5. Ester formation
6. Oxidation