For biosynthetic reasons, saccharides are almost always more abundant in nature as the "D" form, or structurally analogous to D-(+)-glyceraldehyde.[1] However, L-arabinose is in fact more common than D-arabinose in nature and is found in nature as a component of biopolymers such as hemicellulose and pectin. The L-arabinose operon is a very important operon in molecular biology and bioengineering.
A classic method for the organic synthesis of arabinose from glucose is the Wohl degradation.
References
^ For sugars, the D/L nomenclature does not refer to the molecule's optical rotation properties but to its structural analogy to glyceraldehyde.