When glucose reacts with an excess of phenylhydrazine, the major product formed is:

Step-by-step solution

When glucose reacts with an excess of phenylhydrazine (usually three equivalents), it undergoes a series of reactions. First, one molecule of phenylhydrazine reacts with the aldehyde group of glucose to form glucose phenylhydrazone. Second, another molecule of phenylhydrazine oxidizes the adjacent hydroxyl group at the C2 position to a ketone group, while being reduced to aniline and ammonia. Third, a final molecule of phenylhydrazine reacts with the newly formed ketone group to yield a bis-phenylhydrazone derivati