Aromatic aldehydes donot respond to fehlings test because the aldehyde group in case of aromatic aldehydes is directly attached to benzene ring and shows resonance due to which it becomes a strong bond and oxidizing agents like cu are unable to oxidize it to coo- group.

Does Fehling's solution react with aromatic aldehydes?

In aromatic aldehydes, the -CHO group is attached to a benzene ring. ... The oxidizing agents like Cu²⁺ are unable to break that bond, so such aldehydes are unable to show fehling's test.

Which aldehyde does not react with Fehling's solution?

Which of the following compound does not react with Fehling's solution? Aromatic aldehyde i.e., C6H5CHO are not able to reduce Fehling solution but it gives Cannizaros reaction with alkali.