Topic№10: Aldehydes and ketones. Carboxylic and carboxylic acids.

Basic questions:

1. The conception of carbonyl compounds. Aldehydes and ketones. Structure and nomenclature.

2. The general physical properties of aldehydes and ketones.

3. The general characteristic to reactionary ability of carbonyl compounds.

4. Nucleophilic addition reaction of aldehydes and ketones.

a) Formation of a hydrate via a nucleophilic addition(addition of water)

b) Aldol condensation reaction

c) Formation of acetals or hemiacetals via a nucleophilic substitution

5. Oxidation-reduction reaction of aldehydes.

6. Carboxylic acids. Nomenclature. Physical and chemical properties of carboxylic acids.

7. Notion about derivatives of carboxylic acids.

8. Electronic structure of carbonyl groups and carboxylate (acilate) ions. СН-acidity of -carbon atom.

9. Nucleophilic substitution reaction of sp²-hybridization carbon atom:

a) acylation reaction – formation of anhydrates.

b) reaction of complex ester, thioester, amides. Hydrolysis of these compounds.

1) The conception of carbonyl compounds. Aldehydes and ketones, their structure.

Carbonyl compounds are compounds, which contain a carbonyl group C=O.

Structure:

• carbonyl groups consists of a carbon-oxygen double bond

• the bond is polar due to the difference in electronegativity

• aldehydes / ketones differ in what is attached to the carbon

In aldehydes - at least one H attached to the carbonyl group, while in ketones - two carbons attached to the carbonyl group. Nomenclature: The names of aldehydes and ketones are simply derived by dropping "-e" from the root and adding "-al" or "-one" respectively. A position number is needed for ketones since the carbonyl group may be on any number of several carbons in the "middle" of a chain. The carbonyl on the aldehyde is always on the number one carbon so no position number is needed. Carbonyl compound Naming Structure Example Aldehyde   -al Propanal Ketone -one Propanone or acetone (common name)

2) The general physical properties of aldehydes and ketones. Aldehydes and ketones are polar molecules because the C=O bond has a dipole moment: C=O Their polarity makes aldehydes and ketones have higher boiling points than alkenes of similar molecular weight. Aldehydes and ketones are not hydrogen bond donors (they can’t donate a proton); therefore, they have lower boiling points than alcohols of similar molecular weight. Aldehydes and ketones are hydrogen bond acceptors; this makes them have considerable solubility in water. Ketones such as acetone are good solvents because they dissolve both aqueous and organic compounds.