Alcohols,_Phenols,_Thiols,_and_Ethers_Simple.ppt

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1. Alcohols, Phenols,
Thiols, and Ethers
Chapter 13

2. Introduction
•Alcohol –organic compound that contains
a hydroxyl (-OH) group attached to an
alkyl group
•Phenol –organic compound that contains
a hydroxyl (-OH) group attached to an aryl
group
•Ether –organic compound that has two
alkyl or aryl groups attached to the oxygen
atom; can be thought of as a substituted
alcohol.

3. Examples
Alcohols-OH hydroxyl CH
3-OH
CH
3CH
2-OH
Phenols
Ethers -O- CH
3-O-CH
3OH OH

4. Practice Problem 1
Classify each as an alcohol (1), phenol (2), or
an ether (3):
A. _____ CH
3CH
2-O-CH
3C. _____ CH
3CH
2OH
B. _____OH
CH3

5. Solution 1
Classify each as an alcohol (1), phenol (2), or
an ether (3):
A. ____CH
3CH
2-O-CH
3 C. ____CH
3CH
2OH
B. ___OH
CH3

6. Structure and Properties
•R-O-H portion of alcohol is similar to the
structure of water.
–The oxygen and two atoms bonded to it lie in
the same plane.
–The bond angle is 104°
•Hydroxyl groups are very polar because of
significantly different electronegativities.
–Hydrogen bonding can form between alcohol
molecules.

7. Hydrogen BondingR O
H
O
H
H
O
R
H




O
H
H



8. Results of Hydrogen Bonding
•Alcohols boil at much higher temperatures
than hydrocarbons of similar molecular
weight.
•Alcohols with fewer than five carbons are
very soluble in water.
•Alcohols with five to eight carbons are
moderately soluble in water.
•As the nonpolar (R) portion of the alcohol
gets larger, the water solubility decreases.

9. •Very large alcohols are not soluble in
water.
•Hydrophobic –“water fearing”; used to
describe nonpolar region of molecule
•Hydrophilic –“water loving”; used to
describe polar region of molecule
CH
3CH
2CH
2CH
2CH
2CH
2CH
2CH
2CH
2OH
Hydrophobic Hydrophilic
Solubility of Alcohols

10. Solubility of Alcohols
•An increase in the number of hydroxyl
groups will increase the influence of the
polar hydroxyl group.
–Diols and triols are more water soluble
than alcohols with only a single hydroxyl
group.

11. Practice Problem 2
•Circle the more soluble alcohol in each pair.H
3C C
H
2
OH
A. OR
H
3C
H
2
C
C
H
2
H
2
C
OH
B.
OH
OH
OR OH
C. OR
OH

12. Solution 2
•Circle the more soluble alcohol in each pair.H
3C C
H
2
OH
A. OR
H
3C
H
2
C
C
H
2
H
2
C
OH
B.
OH
OH
OR OH
C. OR
OH

13. Nomenclature of Alcohols
•A carbon compound that contain -OH
(hydroxyl) group
•In IUPAC name, the -e in alkane name is
replaced with -ol.
CH
4 methane
CH
3OH methanol (methyl alcohol)
CH
3CH
3 ethane
CH
3CH
2OH ethanol (ethyl alcohol)

14. More Names of Alcohols
•IUPAC names for longer chains number the
chain from the end nearest the -OH group.
CH
3CH
2CH
2OH
OH
CH
3CHCH
3
CH
3 OH
CH
3CHCH
2CH
2CHCH
3

15. Alcohols that contain more than
one hydroxyl group
•Alcohols containing two hydroxyl groups
are named –diols.
•Alcohols containing three hydroxyl groups
are named –triols.
•A number giving the position of each of the
hydroxyl groups is needed in these cases.

16. Practice Problem 3
Name the following alcohols:
A. OH
CH
3CHCHCH
2CH
3
CH
3
OH
B.

17. Solution 3
Name the following alcohols:
A. OH
CH
3CHCHCH
2CH
3
CH
3
OH
B.

18. Homework
Pages 379-380 13.11-
13.14
Page 360 13.1 –13.2
Due Tomorrow!!!!

19. Section 13.3
•It is yourresponsibility to read
over section 13.3 –Medically
Important Alcohols (pgs. 360-
361) and take notes on the
material covered!
•It will be on the weekly quiz
and the test!

20. Classification of Alcohols
•Alcohols can be classified as primary (1°),
secondary (2°), or tertiary (3°) depending on the
number of alkyl groups attached to the carbon
bearing the –OH group.C
H
HH
OH
H
3C C
H
OH
H
H
3C C
CH
3
OH
H H
3C C
CH
3
CH
3
OH
Methanol 1°alcohol 2°alcohol 3°alcohol
ethanol 2-propanol 2-methyl-2-propanol

21. Practice Problem 4
Classify each of the following alcohols
as primary, secondary, tertiary, or
aromatic.
1.1-butanol
2.3-pentanol
3.1-methylcyclopentanol
4.2-methyl-2-pentanol

22. Solution 4
1.1-butanol
2.3-pentanol
3.1-methylcyclopentanol
4.2-methyl-2-pentanol

23. Homework
•Pages 380-381: 13.15,
13.16, 13.18, 13.19, 13.20,
13.21, 13.22, 13.27, and
13.28
Due Tomorrow!

24. Preparation of Alcohols
•REVIEW: Hydration –an addition reaction in
which a water molecule is added to an alkene;
requires acid as catalyst RR
R R
+
H
OH
H+
HR
R
R OH
R
Alkene Water Alcohol
Markovnikov’s rule applies!!

25. Hydration Examples
•Ethene
•1-butene

26. Preparation of Alcohols
•Hydrogenation of aldehydes and ketonesO
R
1 R
2
+
H
H
H
R
2R
1
OH
Catalyst
In an aldehyde, R1 and R2 may be either alkyl groups or H.
In a ketone, R1 and R2 are both alkyl groups.
We will discuss this in more detail in section 14.4.

27. Hydrogenation Examples
•Ethanal
•2-propanone

28. Preparation of Alcohols
YOU TRY THESE!
+

29. Dehydration of Alcohols
•Alcohols undergo dehydration (lose water)
when heating with concentrated sulfuric or
phosphoric acid.
•Dehydration is an example of an
elimination reaction.
•Elimination reaction –a reaction in which a
molecule loses atoms or ions from its
structure.
•Dehydration is opposite of hydration!

30. Dehydration of Alcohols
•General Reaction
•Ethanol
•2-butanolRCH
2
CH
2
OH
H
+
RCH=CH
2
+ H
2
O CH
3
CH
2
OH
H
+ CCCCH
H
HH
HH
OH
H
H
H
H
+
Heat
Heat
Heat

31. Dehydration of Alcohols
•Zaitsev’s rule –in an elimination reaction,
the alkene with the greatest number of
alkyl groups on the double bonded carbon
(more highly substituted alkene) is the
major product of the reaction
•Another example:

32. Oxidation Reactions
•Oxidation –loss of electrons; add O and/or
lose H
•Reduction –gain of electrons; add H
and/or lose O
•Common oxidizing agents:
–Basic potassium permanganate (KMnO
4/OH
-
)
–Chromic Acid (H
2CrO
4)
•[O] Any general oxidizing agent

33. Oxidation of Primary Alcohols
•General equation:
–Primary alcohol aldehyde
RCH
2CH=O
EXAMPLE:
1-propanol

34. Oxidation of Secondary
Alcohols
•General equation:
–Secondary alcohol ketone
O
R-C-R
EXAMPLE:
2-propanol

35. Oxidation of Tertiary Alcohols
•General equation:
–Tertiary alcohol NO REACTION!!!

36. YOU TRY THESE!CCCCH
H
HH
HH
OH
H
H
H
[O]
OH
[O]
OH
[O]
CH
3
CH
2
OH
[O]

37. Phenols
•Phenols –compounds in which the
hydroxyl group is attached to a benzene
ring
•They are polar compounds because of the
polar hydroxyl group.
•Smaller phenols are somewhat soluble in
water.
•They are found in fragrances and
flavorings and are also used as
preservatives and germicides.

38. Common Phenols and their
Uses
CH
3
OH
(CH
3)
2HC Thymol (mint)
CH
3
OH
(CH
3)
2HC
Carvacrol (savory)

39. Common Phenols and their
Uses
OH
(CH
3)
3C
CH
3
C(CH
3)
3
Butylated hydroxytoluene,
BHT(Food preservative)
OH
Phenol
(Carbolic acid when dissolved in water)
Antiseptic and disinfectant used by
Joseph Lister to bathe wounds and sterlize
instruments

40. Ethers

41. Ethers
•What are they?
•How are they used?
•What do you know about them?

42. Structure of Ethers
•Similar structure to alcohols
Alcohols: R-OH
–OH is “hydroxy”group
Ethers: R-OR
–OR is “alkoxy”group

43. Alkoxy group
•“R” groups can be
the same:
CH
3-O-CH
3
•Both “R” groups
have one carbon
•“R” groups can be
different:
CH
3CH
2CH
2-O-CH
3
•One “R” group has
three carbons while
the other has one

44. Alkoxy group
•The root names are used with –oxy to
name that portion of the ether:
–meth-+ -oxy
–eth-+ -oxy
–prop-+ -oxy
= methoxy
= ethoxy
= propoxy

45. Naming ethers –IUPAC Way
1.Find the root name of the smaller “R” group
Ex: meth-, eth-, prop-
2.Add –oxy
Ex: methoxy, ethoxy, propoxy
3.Add the full name of the larger “R” group
EXAMPLE: O
methoxypropane

46. Name that ether

47. O O
O

48. Draw the structure of:
1. methoxypropane
2. methoxyoctane
3. propoxypropane
4. ethoxypentane

49. Naming Ethers –Common
Name
•Name by placing the names of the two alkyl
groups attached to the ether oxygen as words
in front of the word “ether.” Typically this is
done in alphabetical order.O O
O
Diethyl Ether Ethyl methyl ether
Butyl propyl ether

50. Properties of ethers
•The C-O bond in ethers is polar, making
the molecule polar
•Ethers have very low boiling points
•Ethers are relatively inert, but flammable
in air

51. Let’s compare…
Ether
CH
3–O-CH
2CH
3
Molecular Formula:
C
3H
8O
Molecular Weight:
60.09g/mol
Boiling Point:
7.9°C
Alcohol
CH
3CH
2CH
2-OH
Molecular Formula:
C
3H
8O
Molecular Weight:
60.09g/mol
Boiling Point:
97.2°C

52. Preparing ethers
•Ethers are formed from alcohols
R-OH + R’-OH R-O-R’ +H
2O
–R and R’ can be the same or
different
–Called a dehydration reaction
H
+


53. Predict the products

54. CH
3OH + CH
3CH
2OH
H+
CH
3CH
2CH
2OH + CH
3CHCH
3
H+
OH

55. Common uses
•Ethers as anesthetics:
–Penthrane
–Enthrane
•Ethers as additives in gasoline
–MTBE –methyl tert-butyl ether

56. Thiols
•Compounds that contain the sulfhydryl
group (-SH)
•Similar to alcohols in structure, but the
sulfur atom replaces the oxygen atom
•Have nauseating aromas –defense spray
of North American striped skunkH
2C
CH
3H
H
SH
Trans-2-butene-1-thiol

57. Naming Thiols
•Use the same rules as for alcohols except
that the full name of the alkane is retained.
•Add the suffix –thiol.CH
3CH
2SH
CH
3CHCH
2CH
2
CH
3
SH
HSCH
2CH
2SH
ethanethiol
3-methyl-1-butanethiol
1,2-ethanedithiol

58. Uses of Thiols
•Thiols are involved in protein structure and
conformation.
•Cysteine is an amino acid that contains a
sulfhydryl group.
•BAL (British Anti-Lewisite) is used as an
antidote for mercury poisoning.
•Coenzyme A serves as a carrier of acetyl
groups in biochemical reactions.

59. Homework
•Pg. 381-382: 13.43,
13.44, 13.45, 13.48,
13.49, 13.51, 13.52,
13.53, 13.59, 13.60