Chemistry - Carbonyl compounds Question with Solution | TestHub
An optically inactive alcohol (A) C6H12O6 is oxidized by MnO2 to produce optically inactive carbonyl compound while reduction of (A) by H2 /Ni produces optically active compound. Possible structure(s) of alcohol is/are
Options:(select one or more)
Answer:
Solution:
Question Explanation:
Identify the possible structure(s) of the alcohol A based on oxidation and reduction products.
Concept:
Oxidation and Reduction Stereochemistry.
Solution:
1. A (Optically inactive, C₆H₁₂O₆ Ketone (Optically inactive)): A must be a primary allylic alcohol (MnO₂ selectivity) that is achiral and yields an achiral ketone (C₆H₁₀O).
2. Compound (Optically active): Hydrogenation reduces C=C, yielding a chiral alcohol (1 chiral center must be formed).
* A. Hex-2-en-1-ol (CH3CH2CH2CH=CHCH2OH): (Achiral): Oxidation → Hex-2-enal (Achiral).
Reduction → Hexan-1-ol (Achiral). ×
* B. 2-Methylpent-2-en-1-ol (CH3CH2CH=C(CH3)CH2OH) : (Achiral): Oxidation → Aldehyde (Achiral). Reduction → 2-methylpentan-1-ol (Chiral). ✓
* C. 3-Methylpent-2-en-1-ol (CH3CH=C(CH3)CH2CH2OH) (Achiral): Oxidation → Aldehyde.
Reduction → Chiral. ✓
