Question

Which of the following reactions does not give benzaldehyde?

(a) Rosenmund reaction

(b) Etard reaction

(c) Gatterman-Koch reaction

(d) Friedel-Craft acylation reaction

The question was posed to me by my college professor while I was bunking the class.

The query is from Preparation of Aldehydes and Ketones topic in section Aldehydes, Ketones and Carboxylic Acids of Chemistry – Class 12

Answer 1

Right option is (d) Friedel-Craft acylation reaction

To explain I would say: Friedel-Crafts acylation of benzene produces an aromatic ketone and not benzaldehyde. Benzene on Gatterman-Koch reaction gives benzaldehyde, so does toluene on Etard reaction. Rosenmund reaction also gives benzaldehyde but from benzoyl chloride.