Lactaldehyde is an intermediate in the methylglyoxal metabolic pathway.

Methylglyoxal Methylglyoxal (MGO) is the organic compound with the formula CH3C(O)CHO. It is a reduced derivative of pyruvic acid. It is a reactive compound that is implicated in the biology of diabetes. Methylglyoxal is produced industrially by degradation ...

is converted to D-lactaldehyde by glycerol dehydrogenase (gldA). Lactaldehyde is then oxidized to

lactic acid Lactic acid is an organic acid. It has the molecular formula C3H6O3. It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as wel ...

aldehyde dehydrogenase Aldehyde dehydrogenases () are a group of enzymes that catalyse the oxidation of aldehydes. They convert aldehydes (R–C(=O)) to carboxylic acids (R–C(=O)). The oxygen comes from a water molecule. To date, nineteen ALDH genes have ...

Structure

Lactaldehyde is a three-carbon atom species with a

carbonyl group In organic chemistry, a carbonyl group is a functional group with the formula , composed of a carbon atom double-bonded to an oxygen atom, and it is divalent at the C atom. It is common to several classes of organic compounds (such as aldehydes ...

on the first carbon atom (making it an

aldehyde In organic chemistry, an aldehyde () (lat. ''al''cohol ''dehyd''rogenatum, dehydrogenated alcohol) is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred ...

), and a

hydroxy group In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...

on the second carbon atom, making it a secondary

alcohol Alcohol may refer to: Common uses * Alcohol (chemistry), a class of compounds * Ethanol, one of several alcohols, commonly known as alcohol in everyday life ** Alcohol (drug), intoxicant found in alcoholic beverages ** Alcoholic beverage, an alco ...

. The molecule is

chiral Chirality () is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek language, Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is dist ...

, its stereocenter being located on the second carbon atom. Lactaldehyde exists in several forms: in

open-chain In chemistry, an open-chain compound (or open chain compound) or acyclic compound (Greek prefix ''α'' 'without' and ''κύκλος'' 'cycle') is a compound with a linear structure, rather than a cyclic one. An open-chain compound having no side ...

form and as cyclic

hemiacetal In organic chemistry, a hemiacetal is a functional group the general formula , where is a hydrogen atom or an organic substituent. They generally result from the nucleophilic Addition reaction, addition of an Alcohol (chemistry), alcohol (a compo ...

; in solution and in crystal forms; as

monomer A monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or two- or three-dimensional network in a process called polymerization. Classification Chemis ...

and as

dimer Dimer may refer to: * Dimer (chemistry), a chemical structure formed from two similar sub-units ** Protein dimer, a protein quaternary structure ** d-dimer ** TH-dimer * Dimer model, an item in statistical mechanics, based on ''domino tiling'' * ...

. In crystal form, three

conformer A conformer is a clear acrylic shell fitted after an enucleation of the eye Enucleation is the removal of the eye that leaves the eye muscles and remaining orbital contents intact. This type of ocular surgery is indicated for a number of oc ...

s occur as hemiacetal dimers with a 1,4-dioxane ring skeleton: Lactaldehyde dimerization V1

In equilibrium solution, negligibly small amounts of the monomer and at least one five-membered ring dimer exist.

References

{{reflist Hydroxy aldehydes Secondary alcohols