Identify the reagents used for the following conversion

Step-by-Step Explanation:

Step A: Conversion of ester to aldehyde

The ester group (−COOCH₃) is converted to an aldehyde (−CHO).

DIBAL-H (Diisobutylaluminium hydride) is the correct reagent for this reaction, as it reduces esters to aldehydes at low temperatures (-78°C).

LiAlH₄ would reduce the ester completely to a primary alcohol, which is not the desired product.

Reagent A = DIBAL-H

Step B: Aldol condensation

This step involves the reaction of two aldehydes (−CHO) to form a β-hydroxy aldehyde (aldol product), which then undergoes dehydration to form an α,β-unsaturated aldehyde.

NaOH (aqueous) is the standard reagent for aldol condensation. It facilitates the enolate formation and subsequent reaction.

Reagent B = NaOH (aq)

Step C: Cyclization and reduction

The final step involves the conversion of the α,β-unsaturated aldehyde into a saturated cyclic product.

NH₂-NH₂/KOH, ethylene glycol is a Wolff–Kishner reduction, which removes the carbonyl group (aldehyde) and yields the saturated hydrocarbon.

Other options, like Zn/Hg, HCl (Clemmensen reduction), are not consistent with the reaction conditions shown here.

Reagent C = NH₂-NH₂/KOH, ethylene glycol

Correct Answer:

Option B

• A = DIBAL-H
• B = NaOH (aq)
• C = NH₂-NH₂/KOH, ethylene glycol