1. Alcohols, Thiols, and Ethers
Chapter 12
Alcohols, Thiols, and Ethers

2. Alcohols Contain the –OH group as in R-OH. Nomenclature of alcohols:
Find the longest chain of C’s, which also includes the –OH group. Change the –e at the end of the usual base name to –ol.
Number the chain so that the –OH group has the lowest number ALWAYS!!!
Name any other substituents using these numbers.
Cyclic alcohols are named as cycloalkanols.
Benzene ring with an OH is called Phenol.

3. Classification of Alcohols
Alcohols are classified as primary (1o), secondary (2o), or tertiary (3o) based on how many C’s are bonded to the C with the –OH group.
LEP #1
Primary – has one alkyl group
Secondary – has two alkyl groups
Tertiary – has three alkyl groups

4. Thiols Contain the –SH group. Are known as compound with strong odors.
CH3CH2 – SH = Ethane thiol, added to natural gas.
CH3CH2CH2 – SH = Propane thiol, onions.

5. Ethers Contain an O atom between two alkyl groups.
Oxygen atom does have lone pairs and make them slightly polar.
Some ethers with halogens were commonly used as anesthetic agents.

6. Properties of Alcohols, Ethers
Alcohols have Hydrogen Bonding type forces with the –OH group.
This significantly increases their boiling points and solubility in water.
Ethers are only slightly polar and have lower boiling points and limited solubility.
Compound
Molar mass
Boiling pt.
H2O
CH3CH2CH3
44 g/mol
-42oC
insoluble
CH3OCH3
46 g/mol
-23oC
71g / 100mL
CH3CH2OH
78oC
miscible

7. Properties
Solubility of smaller alcohols like methanol and ethanol are said to be miscible.
As the number of C’s increases to three and four, they have a solubility limit.
By the time we get to six C’s, it is insoluble.
CH3-CH2-CH2-CH2-CH2-CH2 - OH
Non-polar carbon chain dominates

8. Properties Environmental Issue – MTBE
Methyl-t-butyl ether or MTBE – once added to gasoline as an “oxygenate.”
Problem: it is slightly soluble in water and is not biodegradable.

9. Properties
Phenol is slightly soluble in water due to the fact that it is a weak acid.

10. Reactions of Alcohols
Depends on the classification (1o, 2o, or 3o) for some reactions.
Oxidation = removal of 2 H atoms OR the addition of an O atom.
Reduction = removal of an O atom OR the addition of 2 H atoms.
I will show the oxidation processes for each type of alcohol. Reduction reverses the process.
[O] = oxidizing agent (KMnO4, K2CrO4)

11. Reactions of Alcohols Primary Ex) CH3CH2OH Secondary Ex) CH3CHCH3  OH
Tertiary
Ex) (CH3)3-C-OH

12. Reactions of Thiols
Oxidation of two thiols produces something called a disulfide.
One amino acid contains this and determines whether you have straight or curly hair.
2 CH3CH2-SH 

13. Aldehydes and Ketones C=O
Carbonyl group, C=O, is polar with a partial negative charge residing on the O atom.
In an aldehyde, the carbonyl group has one or more H atoms bonded to the C atom.
In a ketone, the carbonyl group has two alkyl groups.
C=O d+ d-

14. Aldehydes Naming these replaces the –e in the base name with -al.
Carbon #1 MUST be the carbonyl carbon.
Any other substituents are numbered according to this numbering.

15. Ketones Naming these replaces the –e ending to –one.
Will need a number for position of carbonyl if five or more C’s are present.
Can also have cycloketones – then carbonyl group is C #1.

16. Properties
The boiling points of aldehydes and ketones are higher than those of alkanes and ethers of similar mass.
This is due to the polar carbonyl group.
However, their boiling points are less than those of the alcohols, because the alcohols have Hydrogen Bonding forces.
Name
Butane
Ethyl methyl ether
Propanal
Propanone
1-Propanol
Molar Mass
58 g/mol
60 g/mol BP
0oC
8oC
49oC
56oC
97oC

17. Properties
Aldehydes and Ketones with four or less Carbons are very soluble in water.
Solubility is less than that for similar number of C’s with alcohol group.
Larger ones are not soluble.
Oxidation of aldehydes and ketones is like that for the alcohol series.

18. Chirality
Some molecules have the exact same formula and connections, but differ in their spatial arrangements.
These are called stereoisomers and result from a chiral carbon.

19. Chirality
Decide whether the following objects would be chiral or achiral.

20. Chirality
When a C atom has four different groups bonded to it, it said to be chiral.
The mirror image is of this molecule is NOT the same.
Test = Not Superimposable.
CH3 C H OH Cl

21. Chirality
Which molecules have chiral carbons?

22. Carboxylic Acids, Esters, Amines, and Amides
Ch. 13
Carboxylic Acids, Esters, Amines, and Amides

23. Carboxylic Acids
Contains both the carbonyl group and the hydroxyl groups (-COOH).
Collectively, these two are called the carboxylic group.
The H atom on the hydroxyl group is acidic.

24. Carboxylic Acids Naming:
Identify longest chain with the carboxylic group.
Carboxylic group carbon is C#1.
Any other substituents are numbered based on this carbon.
Aromatic carboxylic acid is called benzoic acid.

25. Properties -OH group forms Hydrogen Bonds
Carbonyl group is also very polar.
Have higher boiling points than alcohols.
1-propanol (bp = 97oC) or ethanoic acid (bp = 118oC) both have molar mass of 60. g/mol.
Acids form a dimer.

26. Properties One to four carbon chain acids are very soluble in water.
For five or more carbon acids, they are only slightly soluble in water.
Carboxylic acids are weak acids.
The H atom on the –OH group can be donated to a a base.
RCOOH + H2O  RCOO- + H3O+

27. Properties
A strong base can be used to neutralize a carboxylic acid to yield water and a salt.
RCOOH + NaOH  RCOO-Na+ + H2O
Some of the “salts” are used as preservatives in food products.
Ex) Sodium propionate and sodium benzoate

28. Reactions
A carboxylic acid will react with an alcohol to form an ester.
O O H+
CH3 C-OH + HO-CH H2O + CH3 C – O – CH3

29. Esters
Are the fragrances of fruits, flavorings, and perfumes.

30. Ester
A fat or oil is a tri-ester of glycerol and three fatty acids (long chain carboxylic acids).
This is the our vegetable oil in the biodiesel project.
In the presence of a strong base (NaOH), the ester will dissociate into the carboxylic acid salt and the alcohol.
The carboxylic acid can then be converted to a single ester with methanol.

31. Amines Amines are derivatives of ammonia (NH3)
Each H atom of ammonia can be replaced by an alkyl group.
Amines are classified as 1o, 2o, and 3o based on how many H atoms are replaced.
Trimethyl amine

32. Properties
Amines with at least one H atom bonded to N will have hydrogen Bonding forces.
Those with HB will have higher boiling points, but less than the alcohols.
Propanol, 97oC; Propyl amine, 48oC, and Trimethylamine, 3oC
Amines are weak bases and will react with water like NH3.
Amine salt = reacting an amine with a strong acid.

33. Alkaloids
Amines are commonly found in plants and may have biological effects.
caffeine

34. Amides
The reaction of a carboxylic acid and an amine produces an amide – similar to ester reaction.
O H O H
heat
CH3CH2 C–OH + H-N-CH H2O + CH3CH2-C-N-CH3
If you have a di-carboxylic acid plus a di-alcohol OR di-amine, then you can make a condensation type polymer.
Ex) Terephthalic acid + Ethylene Glycol
Ex) Hexamethyldiamine + Hexanedioic Acid