1. Alcohols, Phenols, and Thiols
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

2. Alcohols and Ethers
An alcohol contains the hydroxyl (–OH) functional group.
In an ether, an oxygen atom is bonded to two carbon atoms (–C–O–C–).
ethanol chemspider
dimethyl ether Chemspider
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

3. General, Organic, and Biological Chemistry
Thiols
In a thiol, the functional group –SH is bonded to a carbon atom.
ethanthiol
General, Organic, and Biological Chemistry

4. Learning Check 1) CH3–CH2–CH2–OH 2) CH3–O–CH2–CH3 3) CH3–CH2–NH2 O ||
Classify each of the following as alcohol, ether, aldehyde, ketone, carboxylic acid, ester, or amine.
1) CH3–CH2–CH2–OH
2) CH3–O–CH2–CH3
3) CH3–CH2–NH2 O ||
4) CH3–C–OH
5) CH3–C–O–CH3
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

5. General, Organic, and Biological Chemistry
Alcohols and Phenols
An alcohol contains
a hydroxyl group (—OH) attached to a carbon chain
A phenol contains
a hydroxyl group (—OH) attached to a benzene ring
General, Organic, and Biological Chemistry

6. Classification of Alcohols
Alcohols are classified
by the number of alkyl groups attached to the carbon bonded to the hydroxyl
as primary (1°), secondary (2°), or tertiary(3)
Primary (1º) Secondary (2º) Tertiary (3º)
1 group groups 3 groups__ H CH CH | | |
CH3—C—OH CH3—C—OH CH3—C—OH | | | H H CH3
methanol
tert-butanol
2-propanol
butanol
2-butanol
2-ethyl-2-propanol
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

7. Learning Check OH | A. CH3—CH—CH2—CH3 B. CH3—CH2—CH2—OH
Classify each alcohol as P) primary, S) secondary, or T) tertiary. OH |
A. CH3—CH—CH2—CH3
B. CH3—CH2—CH2—OH
C. CH3—CH2—C—CH2—CH3
CH3
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

8. Guide to Naming Alcohols
General, Organic, and Biological Chemistry

9. Naming Alcohols The names of alcohols
in IUPAC system replace -e of alkane name with -ol
that are common names use the name of the alkyl group followed by alcohol
Formula IUPAC Common Name
CH4 Methane
CH3─OH Methanol Methyl alcohol
CH3─CH3 Ethane
CH3─CH2─OH Ethanol Ethyl alcohol
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

10. More Names of Alcohols
In IUPAC names for longer carbon chains, the chain is
numbered from the end nearer the –OH group.
CH3─CH2─CH2─OH Propanol OH │
CH3─CH─CH2─CH Butanol
CH OH
│ │
CH3─CH─CH2─CH2─CH─CH Methyl-2-hexanol
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

11. General, Organic, and Biological Chemistry
Some Typical Alcohols OH |
“Rubbing alcohol”: CH3—CH—CH3
2-Propanol (isopropyl alcohol)
Antifreeze: HO—CH2—CH2—OH
1,2-Ethanediol (ethylene glycol)
Glycerol: HO—CH2—CH—CH2—OH
1,2,3-Propanetriol
General, Organic, and Biological Chemistry

12. Learning Check Give the IUPAC name for each of the following:
A. CH3—CH2—CH2—CH2—OH
OH CH3
| |
B. CH3—CH—CH—CH2—CH3 C.
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

13. Learning Check Draw the condensed structural formula of the following:
A. 3-Pentanol
B. Propyl alcohol
C. 3-Methylcyclohexanol
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

14. Phenols in Medicine Phenol
is the IUPAC name for benzene with a hydroxyl group
is used in antiseptics and disinfectants
Phenol Resorcinol Hexylresoricinol
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

15. Thiols organic compounds that contain a –SH group
are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain
are found in onions, oysters, and garlic - STINKY
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

16. Naming Thiols
In thiols with long carbon chains, the chain is numbered to locate the SH group.
CH3—CH2—CH2—SH 1-Propanethiol SH |
CH3—CH—CH Propanethiol
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

17. General, Organic, and Biological Chemistry
Sources of Thiols
Thiols
often have strong odors
are used to detect gas leaks
are found in onions, oysters, and garlic
General, Organic, and Biological Chemistry

18. Learning Check Draw the condensed structural formula of each of the
following compounds:
A. 2-Butanethiol
B. 2-Methyl-1-butanol
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

19. Learning Check Name each of the following compounds: OH |
A. CH3—CH2 —CH—CH3
CH3
B. CH3—CH2—CH—CH2—CH2—OH
C. CH3—CH2—CH2—SH
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

20. Ethers Ethers contain an ─O─ between two carbon groups
that are simple are named by listing the alkyl names in alphabetical order followed by ether
CH3─O─CH3 CH3─CH2─O─CH3
Dimethyl ether Ethyl methyl ether
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

21. General, Organic, and Biological Chemistry
Ethers as Anesthetics
Anesthetics
inhibit pain signals to the brain
such as ethyl ether, CH3─CH2─O─CH2─CH3, were used for over a century but caused nausea and
were flammable
developed by the1960s were nonflammable
General, Organic, and Biological Chemistry

22. Cyclic Ethers A cyclic ether contains an O atom in a carbon ring
is called a heterocyclic compound
typically has 5 (furan) or 6 atoms (pyran) in the ring
Furan Tetrahydrofuran Pyran ,4-Dioxane
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

23. IUPAC Names for Ethers
In the IUPAC system, the shorter alkyl group and the oxygen are named as an alkoxy group attached to the longer alkane.
Methoxy propane
CH3—O—CH2—CH2—CH3
Numbering the longer alkane gives
1-Methoxypropane
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

24. Boiling Points of Alcohols
contain a strongly electronegative O in the OH groups
form hydrogen bonds between alcohol molecules
have higher boiling points than alkanes and ethers of similar mass
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

25. Boiling Points of Ethers
have an O atom, but no H is attached
cannot form hydrogen bonds between ether molecules
have boiling points similar to alkanes of similar mass
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

26. Solubility of Alcohols and Ethers in Water
Alcohols and ethers are more soluble in water than are alkanes because the oxygen atom hydrogen bonds with water.
Alcohols with 1–4 C atoms are soluble, but alcohols with 5 or more C atoms are not.
General, Organic, and Biological Chemistry

27. Comparing Solubility and Boiling Points
General, Organic, and Biological Chemistry

28. Solubility of Phenol Phenol is soluble in water
has a hydroxyl group that ionizes slightly (so is a weak acid)
is corrosive and irritating to the skin
+ H2O H3O+
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

29. Learning Check Which compound would have the higher boiling
point, ethyl methyl ether or 1-propanol? Explain.
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

30. Learning Check
Which compound would be more soluble in water, ethanol or 2-pentanol? Explain.
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

31. Chapter 13 Alcohols, Phenols, and Thiols
13.4 Reactions of Alcohols and Thiols
Combustion
dehydration to an alkene
2 ROH  ether
Oxidation of 1o to aldehyde (CHO) then carboxylic (COOH)
Oxidation [O] of 2o to ketone R2-C=O
Oxidation [O] of 3o???
Thiol [O] to disulfide
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

32. Combustion of Alcohols
Combustion is the reaction of an alcohol with O2 to produce CO2 and H2O.
CH3─CH2─OH(g) + 3O2(g) CO2(g) + 3H2O(g) + heat
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

33. Dehydration of Alcohols
Dehydration of an alcohol occurs
when heated with an acid catalyst
with the loss of —H and —OH from adjacent carbon atoms
H OH
| | H+, heat
H—C—C—H H—C═C—H + H2O
| | | |
H H H H
alcohol alkene
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

34. What would be the major dehydration products (S’s Rules)?

35. Learning Check
Write the equations for the reactions when 2-propanol undergoes:
A. combustion
B. dehydration
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

36. Oxidation and Reduction
In the oxidation of an organic compound,
there is an increase in the number of C—O bonds
there is a loss of H (as H+ and e-)
In the reduction of an organic compound,
there is an decrease in the number of C—O bonds
there is a gain of H (as H+ and e-)
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

37. Oxidation and Reduction (continued)
H’s are lost
This H is lost
General, Organic, and Biological Chemistry

38. Oxidation of Primary (1) Alcohols
When a primary alcohol is oxidized [O],
one H is removed from the –OH
another –H is removed from the carbon bonded to –OH
an aldehyde is produced
[O]
Primary alcohol Aldehyde
OH O
| [O] ||
CH3—C—H CH3—C—H + H2O | H
Ethanol (ethyl alcohol) Ethanal (acetaldehyde)
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

39. Oxidation of Secondary (2) Alcohols
When a secondary alcohol is oxidized [O],
one H is removed from the –OH
another –H is removed from the carbon bonded to the –OH
a ketone is produced
[O]
Secondary alcohol Ketone
OH O
│ [O] ║
CH3—C—CH CH3—C—CH3 + H2O │
H Propanone(dimethyl ketone,
2-Propanol (isopropyl alcohol) “acetone”)
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

40. Oxidation of Tertiary (3) Alcohols
Tertiary alcohols do not readily oxidize [O]
Tertiary alcohol no reaction OH
│ [O]
CH3─C─CH3 no product │
CH There is no H on the C—OH to oxidize.
2-Methyl-2-propanol
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

41. Learning Check Select the compound that would result for each reaction
of CH3—CH2—CH2—OH.
O ||
1) CH3—CH ═ CH ) CO2 + H2O 3) CH3—CH2—C—H
A. H+, heat
B. [O]
C. O2, heat
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

42. Learning Check OH │ [O] CH3—CH—CH2—CH3 ? O ║
Select the product from the oxidation of OH
│ [O]
CH3—CH—CH2—CH ?
O ║
1) CH3—CH ═ CH—CH ) CH3—C—CH2—CH3 │
3) CO2 + H2O ) CH3—CH—CH2—CH3
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.

43. Oxidation of Thiols When thiols undergo oxidation,
an H atom is lost from two –SH groups
the product is a disulfide
[O]
CH3—SH + HS—CH CH3—S—S—CH3 + H2O
disulfide
General, Organic, and Biological Chemistry Copyright © 2010 Pearson Education, Inc.