Question

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

• A. i) Lindlar’s catalyst, H₂; ii) SnCl₂/HCl; iii) NaBH₄; iv) H₃O⁺
• B. i) Lindlar’s catalyst, H₂; ii) H₃O⁺ ; iii) SnCl₂/HCl; iv) NaBH₄
• C. i) NaBH₄; ii) SnCl₂/HCl; iii) H₃O⁺ ; iv) Lindlar’s catalyst, H₂
• D. i) Lindlar’s catalyst, H²; ii) NaBH₄; iii) SnCl₂/HCl; iv) H₃O⁺

Answer 1

The Correct Option is A, C, D

Reagent Sequence for Compound Transformation 

1. The compound \( P \) contains multiple functional groups, including an ester, a nitrile, and an alkyne.

Reagent Sequence for (C):

1. Step 1: Reduction of ester using \( \text{NaBH}_4 \) forms an alcohol.
2. Step 2: Reduction of nitrile using \( \text{SnCl}_2/\text{HCl} \) gives aldehyde.
3. Step 3: Acidic hydrolysis (\( \text{H}_3\text{O}^+ \)) converts alkyne to a ketone.
4. Step 4: Lindlar’s catalyst reduces alkyne to cis-alkene.

Reagent Sequence for (D):

Similar to (C), but the sequence starts with Lindlar’s catalyst to reduce the alkyne before performing reductions.

Final Conclusion:

The correct pathways result in Q with the desired functional groups.

Answer 2

To solve the problem, we analyze the sequence of reagents needed to convert compound P to compound Q.

1. Understanding the transformation:
- Compound P contains alkynes and ester and nitrile groups.
- Compound Q has diol groups, an aldehyde, and a carboxylic acid.
- The reactions involve selective hydrogenation, reduction, hydrolysis, and oxidation steps.

2. Stepwise analysis of reagents:
- i) Lindlar’s catalyst, H₂: Selectively hydrogenates alkynes to cis-alkenes.
- ii) SnCl₂/HCl: Reduces nitrile (-CN) to aldehyde (-CHO).
- iii) NaBH₄: Reduces aldehydes to alcohols.
- iv) H₃O⁺: Acidic hydrolysis converts ester to carboxylic acid and hydrolyzes acetals or other groups.

3. Correct sequence of reagents:
- i) Lindlar’s catalyst, H₂ (alkyne to alkene)
- ii) SnCl₂/HCl (nitrile to aldehyde)
- iii) NaBH₄ (aldehyde to alcohol)
- iv) H₃O⁺ (ester to acid, other hydrolysis)

4. Corresponding options:
- Option (A): Correct sequence (1, 3, 4)
- Option (C): Contains the same correct sequence though order different, partially correct
- Option (D): Incorrect order for reduction and hydrolysis

Final Answer:
Options (A), (C), and (D) contain the correct reagents 1, 3, and 4 in the sequence needed.