2Hydroxybutanoic

2-Hydroxybutanoic acid, also known as alpha-hydroxybutyric acid, is a four-carbon alpha-hydroxy carboxylic acid. Its chemical formula is C4H8O3 and its molar mass is about 104.1 g/mol. The structure consists of a carboxyl group at one end and a hydroxyl group on the adjacent carbon, giving the formula HOOC-CH(OH)-CH2-CH3. The molecule contains one stereogenic center at carbon-2, so it exists as two enantiomers.

In chemical terms, 2-hydroxybutanoic acid is an example of an alpha-hydroxy acid. It is commonly encountered as a relatively simple building block in organic synthesis and can serve as a precursor to other carbonyl or ester derivatives. It also appears as a minor natural metabolite in some biological systems and can be found in small quantities in certain fermentation products and foods.

Synthesis and applications are mainly in the realm of chemical manufacturing and research. As a versatile intermediate, it can be converted to various esters, amides, and ketones, enabling use in pharmaceutical, flavor, and fragrance chemistry. In cosmetic contexts, alpha-hydroxy acids are known for their role as exfoliating agents, though 2-hydroxybutanoic acid itself is less common in over-the-counter formulations than smaller alpha-hydroxy acids such as glycolic acid.

Safety and handling follow standard practices for organic carboxylic acids. It is a weak acid and, in concentrated form, may be an irritant. Proper labeling, protective equipment, and ventilation are advised in laboratory and industrial settings.