What derivative results when an aldopentose is treated with excess phenylhydrazine and catalytic acid?

Question

Quizplus · Accepted Answer

Treatment of an aldopentose with excess phenylhydrazine and catalytic acid results in the formation of an osazone, which is a derivative specific to carbohydrates. The osazone forms when the phenylhydrazine reacts with the carbonyl group of the aldopentose, followed by an intramolecular cyclization reaction. The specific structure of the osazone formed can be used to identify the aldopentose that was used.

What Derivative Results When an Aldopentose Is Treated with Excess