Aldehydes, Ketones, and Carboxylic Acids

1. Introduction to Carbonyl Compounds

2. Organic compounds containing a carbon-oxygen double bond (carbonyl group) are fundamental in organic chemistry. The nature of the groups attached to the carbonyl carbon determines whether the compound is an aldehyde, ketone, or carboxylic acid.

3. Aldehydes: The carbonyl group is bonded to at least one hydrogen atom.

4. Ketones: The carbonyl group is bonded to two carbon atoms.

5. Carboxylic Acids: The carbonyl group is bonded to a hydroxyl group (-OH).

The general structures are:

• Aldehyde:

• Ketone:

• Carboxylic Acid:

Nomenclature and Structure of Carbonyl Compounds

The naming of carbonyl compounds follows specific rules based on the functional group present. The functional group (F.G.) and the suffix or prefix used in naming are as follows:

• Aldehydes:

  • Functional group:

  • Suffix: -al

  • Prefix: formyl-

• Ketones:

  • Functional group: (within the carbon chain)

  • Suffix: -one

  • Prefix: keto- or oxo-

For carboxylic acids, the suffix -oic acid is used, and the functional group is .

Common Names of Carbonyl Compounds

Many simple carbonyl compounds are known by their common names, which are often derived from Latin or Greek roots indicating the number of carbon atoms.

These prefixes are used in the common names of aldehydes and acids (e.g., formaldehyde, acetic acid).

Examples of Aldehydes and Ketones

Key Points:

• The IUPAC system names aldehydes by replacing the terminal -e of the parent alkane with -al.

• Ketones are named by replacing -e with -one and indicating the position of the carbonyl group if necessary.

• Common names often use the prefixes listed above and may include the names of the alkyl groups attached to the carbonyl carbon.

Summary Table: Suffixes and Prefixes for Carbonyl Compounds

Example: The compound CH3CH2CHO is called propionaldehyde (common name) and propanal (IUPAC name).

Additional info: The study of carbonyl compounds is essential in organic chemistry due to their reactivity and presence in many biological and industrial molecules. Understanding their nomenclature is foundational for further study in organic synthesis and biochemistry.