HOCH2CHO

HOCH2CHO, commonly known as glycolaldehyde, is the simplest hydroxy aldehyde with the formula C2H4O2. Its IUPAC name is 2-hydroxyethanal, and it is also referred to as hydroxyacetaldehyde. The molecule has an aldehyde functional group adjacent to a hydroxymethyl group, giving the structure HO-CH2-CHO. It is a colorless, highly water-soluble compound that is reactive due to the aldehyde group and the neighboring hydroxyl.

Structure and properties

Glycolaldehyde consists of a two-carbon backbone with an aldehyde group on one end and a hydroxyl group on the other. It is typically encountered as a reactive, hygroscopic liquid or in solution. The compound readily undergoes chemical transformations at the aldehyde moiety, including oxidation to glycolic acid and reduction to ethylene glycol. It can also participate in aldol reactions, contributing to the formation of larger sugars.

Preparation and occurrence

Glycolaldehyde is a known product of the formose reaction, in which formaldehyde is disproportionated under basic conditions to yield a mixture of sugars and sugar-like molecules, including glycolaldehyde. In nature, glycolaldehyde has been detected in interstellar space, notably in molecular clouds, where it is considered a potential precursor to ribose and other biologically relevant molecules, highlighting its relevance to prebiotic chemistry.

Reactions and applications

In aqueous media, glycolaldehyde can polymerize, especially under basic conditions, and it is typically stabilized as part of solutions or solutions with scavengers. It serves as a simple building block in organic synthesis for learning about aldehyde and polyol chemistry. Its biological and astrochemical significance stems from its role as one of the simplest sugar-related molecules that can seed more complex carbohydrate chemistry.

See also

2-hydroxyethanal; glycolic acid; ethylene glycol; formose reaction.