See image — Aldehydes Ketones and Carboxylic Acids Chemistry Question

💡 Solution & Explanation

Concept: Hydration of aldehydes in aqueous acid — gem-diol (hydrate) formation. Step 1: Identify the starting material. The substrate is Ph2CH—CHO (diphenylacetaldehyde), an aldehyde with a diphenylmethine group alpha to the carbonyl. Step 2: Understand the reaction. In aqueous acid, aldehydes can form gem-diols (aldehyde hydrates) via nucleophilic addition of water to the carbonyl carbon. The reaction is: R-CHO + H2O ⇌ R-CH(OH)2. Step 3: Apply to substrate. Ph2CH—CHO + H2O → Ph2CH—CH(OH)2. This is a geminal diol where the former aldehyde carbon now bears two OH groups. Step 4: Match to options. Option (c) shows Ph2CH—CH(OH)—OH, which is the geminal diol Ph2CH—CH(OH)2 — this matches exactly. Step 5: Why this product forms in 81% yield. The electron-donating Ph2CH group somewhat destabilizes the cationic transition state, but the reaction still produces the hydrate as the dominant product (81%). The minor products — enol (2%) and aldehyde (17%, likely from Cannizzaro or tautomer pathways) — are present in smaller amounts. Step 6: Eliminate other options. - (a) Ph—C(Ph)=CH—O is an enol ether or vinyl oxide; not the major product. - (b) Ph2CH—CH2OH is the reduced alcohol; would require hydride reduction, not simple aqueous acid. - (d) Ph2CH—CO—CH3 is a ketone rearrangement product; not consistent with major pathway. Therefore, the correct answer is C.