Aldehydes, Ketones, and Carboxylic Acids

Introduction to Carbonyl Compounds

Organic compounds containing a carbon-oxygen double bond (C=O) are known as carbonyl compounds. The carbonyl group is a fundamental functional group in organic chemistry and is present in several important classes of compounds, including aldehydes, ketones, and carboxylic acids.

• Aldehydes: The carbonyl group is bonded to at least one hydrogen atom. General formula: R-CHO

• Ketones: The carbonyl group is bonded to two carbon atoms. General formula: R-CO-R'

• Carboxylic Acids: The carbonyl group is bonded to a hydroxyl group (-OH). General formula: R-COOH

Nomenclature and Structure of Carbonyl Groups

Functional Groups and Naming Conventions

The nomenclature of aldehydes and ketones is based on the position and nature of the carbonyl group. The suffixes and prefixes used in naming these compounds are as follows:

• Aldehydes:

  • Functional group: -CHO

  • Suffix used: -al (e.g., ethanal)

  • Prefix used: formyl-

• Ketones:

  • Functional group: >C=O (within the carbon chain)

  • Suffix used: -one (e.g., propanone)

  • Prefix used: keto- or oxo-

Example: The compound with the structure CH3CHO is named ethanal (IUPAC) or acetaldehyde (common name).

Common Names of Aldehydes and Ketones

Root Names Based on Carbon Chain Length

Common names for aldehydes and ketones are often derived from the number of carbon atoms in the molecule. The following table summarizes the root names:

Examples of Common and IUPAC Names:

Application: Understanding the nomenclature and structure of carbonyl compounds is essential for identifying and predicting the reactivity of organic molecules in chemical reactions.