Unit 4, Topic 4:

Alcohols and Ethers (1.4)

Lesson Instructions

Review the learning goals and success criteria for Topic 4: Alcohols and Ethers.
- Review the minds on, action, and consolidation sections of the lesson, completing any tasks as outlined.
- Complete the fill-in-the-blanks handouts that have been provided to you. They have been linked below.
- Practice and apply what you've learned by completing the practice tasks outlined at the end of the lesson.

Learning Goals

I am learning to ...

- Name and draw alcohols.
- Name and draw ethers.

Minds On

Organic Compounds - Alcohols

Alcohols have a hydroxyl R-OH functional group. (Note R represents the parent chain).

Properties of Alcohols

- Extremely flammable; highly poisonous.
- Smaller alcohols are more polar than longer chain alcohols.
- H-bonding allows for great solubility in water and high melting/boiling points.
- Solubility decreases with increasing chain length.
- Boiling point increases with increasing chain length.

Figure 1. Have you ever wondered where peppermint gets it's "minty" flavouring? It's from the organic alcohol known as "menthol" (common name). The IUPAC name for menthol is: 2-isopropyl-5-methylcyclohexanol.

Organic Compounds - Ethers

Ethers contain two alkyl groups joined by an oxygen atom (R-O-R).

Properties of Ethers

- Ethers are less polar than alcohols. Ether can bond with water by Hydrogen bonds but not other ether molecules.
- Ethers have lower melting/boiling points than comparable alcohols.
- Ethers are soluble in water; solubility decreases with increased chain length (number of carbon atoms).
- Ethers are extremely flammable.

Figure 2. Many common deodorants contain the ether PPG-14 butyl ether. The IUPAC name for this compound is 1-(2-Butoxy-1-methylethoxy)propan-2-ol. The PPG stands for propylene glycol. This additive helps the deodorant to penetrate the skin upon application.

Action

Alcohols

- An alcohol is an organic compound that contains the hydroxyl functional group (-OH).
- The general formula is R-OH, where R represents the parent chain.
- Alcohols can be classified as primary (1°), secondary (2°), or tertiary (3°) alcohols.

Primary alcohols (1°)

- These are alcohols in which the hydroxyl functional group is attached to a carbon which is only attached to one other carbon.

Secondary alcohols (2°)

- These are alcohols in which the hydroxyl functional group is attached to a carbon which is itself attached to two other carbon atoms.

Tertiary alcohols (3°)

- These are alcohols in which the hydroxyl functional group is attached to a carbon which is itself attached to three other carbon atoms.

NAMING AN ALCOHOL

1. Find the longest chain that contains the -OH group.
2. Name the parent chain, replace the -e ending with -ol.
3. For more than one -OH group, use prefixes (diol, triol, etc.).
4. Number the parent chain to give priority to -OH.
5. Include the position number of -OH in front of the -ol ending.
6. Number and name any alkyl substituents.
7. If another functional group has priority over the alcohol, the alcohol substituent is named -hydroxy.

Practice - Naming Alcohols

Example 1. Name the following compound.

Figure 3. 5-methylhexan-3-ol or 5-methyl-3-hexanol.

Example 2. Name the following compound.

Figure 4. 3-methyl-pentan-1-ol or 3-methyl-1-pentanol.

Example 3. Name the following compound.

Figure 5. pent-3-en-2-ol.

Example 4. Name the following compound.

Figure 6. butane-1,3-diol or 1,3-butanediol.

Example 5. Name the following alcohol.

Figure 7. phenol.

Example 6. Name the following aromatic alcohol.

Figure 8. benzene-1,2-diol or 1,2-benzenediol.

Ethers

An ether is an organic compound that contains a functional group in which an oxygen atom is bonded between 2 carbon atoms within a chain.
In other words, there are two alkyl groups joined by an oxygen atom.
Another example of an Ether is their use as anesthetics.

Figure 9. R and R' represent the two alkyl groups on either side of the oxygen.

NAMING AN ETHER

1. Name the longest chain as the parent chain (i.e. you need to determine which is longer, R or R').
2. Name the alkyl substituent attached to the oxygen, change the ending from -yl to -oxy.
3. Include the position # in front showing where the oxygen is attached to the parent chain.
4. Number and name any alkyl substituents.
5. -oxy substituents are listed before alkyl substituents.

Practice - Naming & Drawing Ethers

Example 7. Name the following ether.

Figure 10. 1-methoxypropane.

Example 8. Name the following ether.

Figure 11. 2-ethoxypropane.

Example 9. Name the following ether.

Figure 12. ethoxyethene.

Example 10. Name the following ether.

Note: oxy substituents are listed before alkyl substituents.

Figure 13. 3-methoxy-2-methylhexane.

Example 11. Draw the following ether.

2-methoxy-3-ethylpent-4-ene

Additional Practice - Naming & Drawing Alcohols and Ethers

These questions are not included on the fill-in-the-blanks notes, however, they are available for extra practice. Attempt the naming and drawing of alcohols and ethers, then click to reveal the correct answer.

1. Name the following compound. (Show Answer)

2. Name the following compound. (Show Answer)

3. Draw the following compound. (Show Answer)

pentan-2-ol

4. Draw the following compound. (Show Answer)

1-ethoxybutane

5. Draw the following compound. (Show Answer)

1,2,3-propanetriol

6. Draw the following compound. (Show Answer)

cyclohex-3-en-1-ol

7. Draw the following compound. (Show Answer)

2-methoxy-2-methylpropane

8. Draw the following compound. (Show Answer)

4-ethoxy-2-methylhex-1-ene

9. Name the following compound. (Show Answer)

10. Draw the following compound. (Show Answer)

2,2,4,4-tetramethylcyclobutane-1,3-diol

This lesson is now complete. Consolidate your learning by evaluating the self-check below and the assigned practice questions.

Self-Check

(This is a self-assessment of your learning – you do not need to submit this).

How prepared am I to start my homework? Can I ...

- name and draw alcohols?
- name and draw ethers?

Practice

Using your textbook, complete the following questions:

- p34 # 1, 2
- p38 # 1, 2
- p39 # 1a-g, 2a-c, e, f

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