Definition

Noun: 1. A specific organic compound: An aldol is an organic molecule, specifically a β-hydroxy aldehyde or ketone. It is formed by a chemical reaction (the aldol reaction or aldol condensation) between two carbonyl compounds, typically aldehydes or ketones. The classic example is the product from the reaction of two acetaldehyde molecules.

Usage

• The term aldol is used primarily in the fields of organic chemistry and biochemistry.
• It refers to both the general structural class of compounds (containing both an alcohol and an aldehyde or ketone group on adjacent carbon atoms) and to specific compounds, such as the one formed from acetaldehyde.
• Example: "The first step in the pathway is the formation of an aldol intermediate."

Examples

• "In the laboratory, we synthesized aldol from acetaldehyde using a base catalyst."
• "The aldol condensation is a fundamental carbon-carbon bond-forming reaction in organic synthesis."
• "This molecule is classified as an aldol due to its β-hydroxy carbonyl structure."

Advanced Usage

• Aldol Reaction: The chemical reaction that forms an aldol through the addition of an enol or enolate to a carbonyl compound.
• Aldol Condensation: A subsequent dehydration reaction where the initial aldol product loses water to form an α,β-unsaturated carbonyl compound.
• Retro-aldol Reaction: The reverse process, where an aldol cleaves to form two smaller carbonyl compounds.

Variants and Related Words

• Aldolase (n): An enzyme that catalyzes the reversible aldol reaction or retro-aldol reaction, crucial in metabolic pathways like glycolysis.
• Aldolization (n): The process of undergoing an aldol reaction.

Synonyms

• β-Hydroxy aldehyde (when the carbonyl is an aldehyde)
• β-Hydroxy ketone (when the carbonyl is a ketone)
• Aldol adduct (specifically the initial product of the addition reaction)

Notes on Meaning

The core meaning of aldol is chemical. It does not have everyday, idiomatic, or phrasal verb uses. Its definition is tightly bound to its specific structure and the reaction that creates it.

Noun

1. an oily colorless liquid obtained by the condensation of two molecules of acetaldehyde; contains an alcohol group (-OH) and an aldehyde group (-CHO)