4.9 Aldehydes and Ketones

What is oxidation

Oxidation is the process of increasing oxygen bonding or decreases hydrogen bonding

What are the types of alcohols

• Primary → the carbon the OH is bound to is only bound to one other carbon

• Secondary → the carbon the OH is bound to is bound to 2 other carbons

• Tertiary → the carbon the OH is bound to is bound to 3 other carbons

What is the product of the oxidation of a primary alcohol

A primary alcohol, when reacted with an oxidizing reagent, [O], forms an aldehyde and water

What is the product of the oxidation of a secondary alcohol

A secondary alcohol, when reacted with an oxidizing reagent, [O], forms a ketone and water

What is the product of the oxidation of a tertiary alcohol

The oxidation of a tertiary alcohol has no reaction, as the tertiary carbon cannot form a carbonyl due to the maximum number of bonds being reached.

What are the two types of non-alcohol oxidations

• Oxidation of an alkene → When oxidized with an oxidizing reagent and water, form two OH bonds on each previously double-bonded carbon

• Oxidation of an aldehyde → When oxidized with an oxidizing reagent, an OH is added.

What is reduction

Reduction is the removal of an oxygen bond or the addition of hydrogen

• opposite of oxidation and returns aldehydes/ketones into alcohols

This is the exact opposite process of any oxidation and requires a metal catalyst, hydrogen, pressure, and heat.

How to name an Aldehyde

• Step 1: Change the ending of the parent chain from “-e” to "-al." (location is not necessary because aldehyde carbonyls are always carbon number 1)

• Step 2: Carbonyls take priority over all previously seen side groups and must be given the smallest possible carbon number.

• Step 3: If carbonyl is not the priority, it is providing the substituent name "oxo."

How to name a Ketone

• Step 1: Change the ending of the parent chain from “-e” to "-one."

• Step 2: Carbonyls take priority over all previously seen side groups and must be given the smallest possible carbon number

• Step 3: If carbonyl is not the priority, it is providing the substituent name "oxo."

Solubility and Polarity of Aldehydes and Ketones

Carbonyls are extremely polar, so aldehydes and ketones are polar molecules.

They cannot form hydrogen bonds between themselves due to lack of an OH group but can form hydrogen bonds in water, allowing for solubility in water.

M/B points of Aldehydes and Ketones in comparison to alkanes and alcohols with the same number of carbons.

Because of this lack of hydrogen bonding between themselves, they have a lower M/B points than corresponding alcohols but because of the high polarity of carbonyls, have higher B points than corresponding alkanes.