Acetaldehyde (systematically: ethanal) is an organic chemical compound with the formula CH3CHO or MeCHO. It is a flammable liquid. Acetaldehyde occurs naturally in ripe fruit, coffee, and bread, and is produced by plants as part of their normal metabolism.

Anisaldehyde, or anisic aldehyde, is an organic compound that consists of a benzene ring substituted with an aldehyde and a methoxy group. It is a clear colorless liquid with a strong aroma.

Benzaldehyde (C₆H₅COH) is an organic compound consisting of a benzene ring with a formyl substituent. It is the simplest aromatic aldehyde and one of the most industrially useful.

Butyraldehyde, also known as butanal, is an organic compound with the formula CH₃(CH₂)2CHO. This compound is the aldehyde derivative of butane. I

Chloroacetaldehyde is the organic compound with the formula ClCH2CHO. Like some related compounds, it is highly electrophilic reagent and a potentially dangerous alkylating agent.

Cinnamaldehyde is the organic compound that gives cinnamon its flavor and odor.[1] This pale yellow viscous liquid occurs naturally in the bark of cinnamon trees and other species of the genus Cinnamomum

A dialdehyde is an organic compound with two aldehyde groups. An example is pentanedial (glutaraldehyde).

Formaldehyde (systematic name: methanal) is a chemical compound with the formula CH₂O. It is the simplest aldehyde. Formaldehyde also exists as the cyclic trimer trioxane and the polymer paraformaldehyde.