Lxylofuranose

L-xylofuranose is the enantiomer of xylofuranose, the five-membered ring (furanose) form of the aldopentose xylose. In solution, xylose can cyclize to a furanose ring, and the L- form denotes the mirror-image configuration of the more common D-xylofuranose. Like other sugar furanoses, L-xylofuranose exists as two anomers, alpha and beta, depending on the orientation of the hydroxyl group at the anomeric carbon (C1).

The furanose ring consists of four carbon atoms and one ring oxygen, with the anomeric carbon at C1 bearing a hydroxyl group that can be oriented up or down relative to the ring. The L designation applies to the stereochemistry at the chiral centers, indicating that it is the opposite configuration to the corresponding D form when compared to the standard Fischer projection used for sugars.

Natural occurrence and use: D-xylofuranose is the form more commonly encountered in biology, often as part of plant polysaccharides such as xylans. L-xylofuranose is not commonly found in nature and is primarily of interest in carbohydrate chemistry as the enantiomeric counterpart; it is typically obtained through synthetic routes or resolution of racemic mixtures and studied for stereochemical, biochemical, and synthetic purposes.

Chemical properties and reactions: As a reducing sugar, L-xylofuranose can equilibrate between open-chain and cyclic forms and can participate in glycosidic bond formation to yield L-xylofuranose-containing oligosaccharides. It undergoes mutarotation between its alpha and beta furanose forms in solution, and its reactivity follows general aldose chemistry, with the aldehyde group exposed in the open-chain form.