Which D-aldopentose is oxidized to an optically active aldaric acid and undergoes the Wolf degradation to yield a D-aldotetrose that is oxidized to an optically active aldaric acid?

A monosaccharide consisting of an aldehyde and five carbon atoms is termed aldopentose. A few examples of aldopentoses are arabinose and xylose.

A monosaccharide possessing four carbon atoms and an aldehyde is termed aldotetrose. Several aldotetroses are present, and one among them is the erythrose.

Optically active aldaric acids are acquired due to the oxidation of two D-aldopentoses (A’ and A’’). The structure of the aldaric acids are given as:

Structure of the aldaric acidsCompound A’’ gets subjected to Wohl degradation forming an aldotetrose. This gets oxidized to an optically active aldaric acid. The structure of D-aldopentose is A’’. The structure can be given as:

Structure of D-aldopentoseThe structure of the aldotetrose can be given as:

Structure of aldotetrose