Threose
d-Threose | |
l-Threose | |
| Names | |
|---|---|
| IUPAC names
d-Threose l-Threose | |
| Systematic IUPAC name
(2S,3R)-2,3,4-Trihydroxybutanal (d) (2R,3S)-2,3,4-Trihydroxybutanal (l) | |
| Other names
Threotetrose | |
| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.002.199 |
PubChem CID |
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| UNII |
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CompTox Dashboard (EPA) |
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| Properties | |
| C4H8O4 | |
| Molar mass | 120.104 g·mol−1 |
| Appearance | Syrup |
| Very soluble | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references | |
Threose is a four-carbon monosaccharide with molecular formula C4H8O4. It has a terminal aldehyde group, rather than a ketone, in its linear chain and so is considered part of the aldose family of monosaccharides. The threose name can be used to refer to both the d- and l-stereoisomers and more generally to the racemic mixture (d/L-, equal parts D- and L-) as well as to the more generic threose structure (absolute stereochemistry unspecified).
The prefix "threo-" which derives from threose (and "erythro-" from a corresponding diastereomer erythrose) offer a useful way to describe general organic structures with adjacent chiral centers, where "the prefixes... designate the relative configuration of the centers". As is depicted in a Fischer projection of d-threose, the adjacent substituents will have a syn orientation in the isomer referred to as "threo", and are anti in the isomer referred to as "erythro".
Although often inconsequential, threose in aqueous solution mainly exists as the hydrate owing to the following equilibrium:
- HOCH2CH(OH)CH(OH)CHO + H2O ⇌ HOCH2CH(OH)CH(OH)CH(OH)2