Question

The option(s) with the correct sequence of reagents for the conversion of P to Q is (are):

• A. i) Lindlar’s catalyst, \(H_2\); ii) \(SnCl_2/HCl\); iii) \(NaBH_4\); iv) \(H_3O^+\)
• B. i) Lindlar’s catalyst, \(H_2\); ii) \(H_3O^+\); iii) \(SnCl_2/HCl\); iv) \(NaBH_4\)
• C. i) \(NaBH_4\); ii) \(SnCl_2/HCl\); iii) \(H_3O^+\); iv) Lindlar’s catalyst, \(H_2\)
• D. i) Lindlar’s catalyst, \(H_2\); ii) \(NaBH_4\); iii) \(SnCl_2/HCl\); iv) \(H_3O^+\)

Hint:

Identify functional group transformations step-by-step based on the reagents provided.

Answer 1

The Correct Option is C

1. The compound \(P\) contains multiple functional groups, including an ester, a nitrile, and an alkyne. 2. Reagent sequence for (C): - Step 1: Reduction of ester using \(NaBH_4\) forms an alcohol. - Step 2: Reduction of nitrile using \(SnCl_2/HCl\) gives aldehyde. - Step 3: Acidic hydrolysis (\(H_3O^+\)) to convert alkyne to a ketone. - Step 4: Lindlar’s catalyst reduces alkyne to cis-alkene. 3. Reagent sequence for (D): - Similar to (C), but the sequence starts with Lindlar’s catalyst to reduce the alkyne before performing reductions. The correct pathways result in \(Q\) with the desired functional groups.