Threose Explained

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".^[1] 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".^{[1] [2]}

See also

• Threitol
• Threonic acid
• Threose nucleic acid

Notes and References

1. http://www2.chemistry.msu.edu:80/faculty/reusch/VirtTxtJml/sterism3.htm#isom17b Formulas Using Other Configurational Notations
2. Prof. Rausch helpfully notes that the prefixes "may be applied to racemic compounds, as well as pure enantiomers and meso compounds", and that when depicted in the common "zig-zag" representation, adjacent "substituents may lie on the same side of the carbon chain... [syn] or on opposite sides... [anti]", which is opposite of their depiction in a Fischer projection.