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 CH3CH2-OH Alcohols -OH hydroxyl CH3-OH Phenols
Ethers -O CH3-O-CH3

4. Practice Problem 1
Classify each as an alcohol (1), phenol (2), or an ether (3):
A. _____ CH3CH2-O-CH3 C. _____ CH3CH2OH
B. _____

5. Solution 1
Classify each as an alcohol (1), phenol (2), or an ether (3):
A. ____ CH3CH2-O-CH3 C. ____ CH3CH2OH
B. _ __

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 Bonding

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. Solubility of Alcohols
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
CH3CH2CH2CH2CH2CH2CH2CH2CH2OH
Hydrophobic
Hydrophilic

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.

12. Solution 2
Circle the more soluble alcohol in each pair.

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 methane
CH3OH methanol (methyl alcohol)
CH3CH3 ethane
CH3CH2OH ethanol (ethyl alcohol)

14. More Names of Alcohols
IUPAC names for longer chains number the chain from the end nearest the -OH group.
CH3CH2CH2OH OH
CH3CHCH3
CH OH
CH3CHCH2CH2CHCH3

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 CH3CHCHCH2CH3

17. Solution 3
Name the following alcohols:
A OH
CH3CHCHCH2CH3
CH3 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 your responsibility to read over section 13.3 – Medically Important Alcohols (pgs ) 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.
Methanol ° alcohol ° alcohol ° alcohol
ethanol propanol methyl-2-propanol

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

22. Solution 4 1-butanol 3-pentanol 1-methylcyclopentanol
2-methyl-2-pentanol

23. Homework
Pages : 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
Alkene Water Alcohol
Markovnikov’s rule applies!!

25. Hydration Examples
Ethene
1-butene

26. Preparation of Alcohols
Hydrogenation of aldehydes and ketones
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-butanol
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 (KMnO4/OH-)
Chromic Acid (H2CrO4)
[O] Any general oxidizing agent

33. Oxidation of Primary Alcohols
General equation:
Primary alcohol aldehyde
RCH2CH=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!

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
CH3 OH
(CH3)2HC
Thymol (mint)
(CH3)2HC
CH3
Carvacrol (savory) OH

39. Common Phenols and their UsesOH
(CH3)3C
CH3
C(CH3)3
Butylated hydroxytoluene,
BHT(Food preservative)
Phenol
(Carbolic acid when dissolved in water)
Antiseptic and disinfectant used by
Joseph Lister to bathe wounds and sterlize
instruments OH

40. Ethers

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

42. Similar structure to alcohols
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: “R” groups can be different:
CH3-O-CH3
Both “R” groups have one carbon
“R” groups can be different:
CH3CH2CH2-O-CH3
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
Find the root name of the smaller “R” group Ex: meth-, eth-, prop-
Add –oxy
Ex: methoxy, ethoxy, propoxy
Add the full name of the larger “R” group
EXAMPLE:
methoxypropane

46. Name that ether

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.
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 CH3 –O-CH2CH3 Molecular Formula: C3H8O
Molecular Weight:
60.09g/mol
Boiling Point:
7.9°C
Alcohol
CH3CH2CH2-OH
Molecular Formula:
C3H8O
Molecular Weight:
60.09g/mol
Boiling Point:
97.2°C

52. R-OH + R’-OH  R-O-R’ +H2O
Preparing ethers
Ethers are formed from alcohols
R-OH + R’-OH  R-O-R’ +H2O
R and R’ can be the same or different
Called a dehydration reaction H+ 

53. Predict the products

55. Common uses Ethers as anesthetics: Ethers as additives in gasoline
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 skunk
Trans-2-butene-1-thiol

57. Naming Thiols ethanethiol 3-methyl-1-butanethiol 1,2-ethanedithiol
Use the same rules as for alcohols except that the full name of the alkane is retained.
Add the suffix –thiol.
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 : 13.43, 13.44, 13.45, 13.48, 13.49, 13.51, 13.52, 13.53, 13.59, 13.60