Unit 3, Topic 3:

Functional Groups, Part 1

Alcohols, Ethers, Aldehydes and Ketones

Lesson Instructions

Review the learning goals and success criteria for Topic 3: Functional Groups, Part 1.
- 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 ...

- Identify, name, and draw alcohols.
- Identify, name, and draw ethers.
- Identify, name, and draw aldehydes.
- Identify, name, and draw ketones.

Minds-On

In this lesson we are learning about Alcohols, Ethers, Aldehydes and Ketones. Let's take a look at some of these common organic compounds.

Organic Functional Group - 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 Functional Group - 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.

Organic Functional Group - Aldehydes

Example: Cinnamon

One of my favourite flavours and odors is cinnamon. Whether it's brewed with my coffee (yes, I do this), or in a cinnabon, I just can't get enough of it. Have you ever wondered where cinnamon gets these awesome properties? It's actually from the aldehyde known as "cinnamaldehyde".

"Cinnamaldehyde occurs naturally in the bark of cinnamon trees and other species of the genus Cinnamomum like camphor and cassia. These trees are the natural source of cinnamon, and the essential oil of cinnamon bark is about 90% cinnamaldehyde. Cinnamaldehyde is also used as a fungicide. Proven effective on over 40 different crops, cinnamaldehyde is typically applied to the root systems of plants. Its low toxicity and well-known properties make it ideal for agriculture. To a lesser extent, cinnamaldehyde is an effective insecticide, and its scent is also known to repel animals like cats and dogs. Cinnamaldehyde is also known as a corrosion inhibitor for steel and other ferrous alloys in corrosive fluids. It can be used in combination with additional components such as dispersing agents, solvents and other surfactants. Concentrated cinnamaldehyde is a skin irritant, and the chemical is toxic in large doses, but no agencies suspect the compound is a carcinogen or poses a long-term health hazard. Most cinnamaldehyde is excreted in urine as cinnamic acid, an oxidized form of cinnamaldehyde."

Retrieved from: https://hmdb.ca/metabolites/HMDB0003441

Organic Functional Group - Ketones

Example: Ketogenesis

Have you ever heard of the term, ketosis? A common method of burning body fat is consuming a low-carb diet. Our body utilizes carbohydrates stored in tissues as its primary source of energy production. As we deprive our bodies of carbohydrates (i.e. less than 50g per day), the secretion of insulin is reduced and the body enters a catabolic state. As glycogen stores deplete, the body is forced to undergo metabolic changes – it needs a new energy source! The two different metabolic processes are called gluconeogenesis and ketogenesis.

Gluconeogenesis is defined as the, "endogenous production of glucose in the body, especially in the liver, primarily from lactic acid, glycerol, and the amino acids, alanine and glutamine". Due to the increasingly unavailable glucose, our bodies cannot keep up with this endogenous production, and thus, ketogenesis kicks in!

Ketogenesis provides the body with this alternate source of energy – ketones! The body has the unique ability to use ketones as an energy source once all of the body's glucose stores have been depleted. Once in ketosis, the body reduces its need to store fat and glucose in our tissues because of "low glucose feedback," and "low stimulus for insulin secretion." Ketogenesis and other hormonal changes in the body metabolize fatty acids to acetoacetate, which is converted to beta-hydroxybutyrate and acetone. These are the ketones that accumulate in our body when sustaining a ketogenic diet. As long as our bodies are deprived of carbohydrates, it will remain in ketosis.

Ketone bodies are known as super fuels! They produce more ATP compared to glucose. 100 grams of acetoacetate generates 9400 grams of ATP, and 100 grams of beta-hydroxybutyrate generates 10,500 grams of ATP. For comparison, 100 grams of glucose produced 8700 grams of ATP. This means when consuming a diet that maintains a caloric deficit (keep in mind BMR, BMI, and body fat), there is efficient fuel production.

Ketone bodies are known to decrease free radical damage (oxidation) and enhance antioxidant capacity.

Retrieved from: Masood W, Annamaraju P, Uppaluri KR. Ketogenic Diet. [Updated 2020 Mar 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499830/

We will now learn how to identify, name, and draw Aldehydes and Ketones!

Action

What is a functional group?

- A functional group is a combination of atoms that determine the physical and chemical characteristics of a compound.

Carbon-Carbon Double or Triple bonds

- Double and triple bonds are easier to break than single bonds.
- Therefore, compounds containing these are more reactive than those with single bonds.

Alcohols

- are hydrocarbons that contain the -OH (hydroxy) functional group. [ending: -ol].

The general notation for an alcohol is R-OH (R implies a general alkane chain).

Here are some examples of alcohols:

methanol, CH₃OH (from methane, a toxic compound)
ethanol, CH₃CH₂OH (beer, wine, and other alcoholic beverages)
propan-2-ol, CH₃CH(OH)CH₃ (rubbing alcohol)

NAMING ALCOHOLS

- Locate the longest chain that contains the -OH group and name it using the same rules from alkanes, alkenes, and alkynes.
- Remove the -e from the end of the parent chain name and replace it with -ol.
  - ex: butane → butanol
- Add a position number to show the position of the -OH group. The -OH group should be in a low position number.
  - ex: butanol → butan-2-ol
- Number and name any alkyl branches.
  - ex: 2-methylbutan-2-ol

PRACTICE NAMING ALCOHOLS

EXAMPLE 1. NAME THE FOLLOWING ALCOHOL.

EXAMPLE 2. NAME THE FOLLOWING ALCOHOL.

EXAMPLE 3. NAME THE FOLLOWING ALCOHOL.

EXAMPLE 4. NAME THE FOLLOWING ALCOHOL.

Ethers

- are hydrocarbons that contain two hydrocarbon alkyl chains joined by an oxygen atom, -O-. [ending: -oxy and -ane].

The general notation for an ether is R-O-R’ (R implies a general alkane chain).

NAMING ETHERS

- Name the longest alkyl chain as the parent chain.
- For the 2nd, short chain, drop the -yl ending and replace it with -oxy.
- Indicate the position number where the oxygen attaches to the parent chain.
- Add the two names together.

PRACTICE NAMING ETHERS

EXAMPLE 1. NAME THE FOLLOWING ETHER.

EXAMPLE 2. NAME THE FOLLOWING ETHER.

EXAMPLE 3. NAME THE FOLLOWING ETHER.

Aldehydes

- are hydrocarbons that contain a C=O functional group at the end of a parent chain. [ending: -al].

This is the general notation for an aldehyde:

NAMING ALDEHYDES

- Identify the parent chain and replace the ending -ane to -al.
- Start numbering the parent chain so that the aldehyde group is at position #1.
- The position number of the aldehyde does not need to be included in the name.

PRACTICE NAMING ALDEHYDES

EXAMPLE 1. NAME THE FOLLOWING ALDEHYDE.

EXAMPLE 2. NAME THE FOLLOWING ALDEHYDE.

EXAMPLE 3. NAME THE FOLLOWING ALDEHYDE.

Ketones

- are hydrocarbons that contain a C=O functional group within a parent chain. [ending: -one]

This is the general notation for an ketone:

NAMING KETONES

- Identify the parent chain and replace the ending -ane with -one.
- Number the parent chain so that the ketone has the lowest possible position number.
- Identify the position number of the ketone in the same.

PRACTICE NAMING KETONES

EXAMPLE 1. NAME THE FOLLOWING KETONE.

EXAMPLE 2. NAME THE FOLLOWING KETONE.

EXAMPLE 3. NAME THE FOLLOWING KETONE.

Consolidation

To consolidate your learning of alcohols, ethers, aldehydes, and ketones, complete the following practice questions.

Once you have complete the practice questions above, check your answers using the solutions below. Make note of any corrections you need to make. Then, upload your completed homework questions on D2L.

This lesson is now complete. Return to D2L - Brightspace and complete the assigned tasks to consolidate your learning.

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