Chemistry - Carbonyl compounds Question with Solution | TestHub

Question Explanation:

Evaluate the Assertion (A) and Reason (R) regarding Chloral's reaction with NaOH. 

Concept:

Haloform Reaction (Chloral Cleavage) vs Cannizzaro Reaction. 

Solution:

Assertion (A): $CC{l}_{3}CHO\stackrel{NaOH}{\to }CC{l}_{3}C{H}_{2}OH+CC{l}_{3}COONa$. Chloral ($CC{l}_{3}CHO$) has no $\alpha$-H (all $\alpha$-positions are Cl). Since it's an aldehyde with no $\alpha$-H, it should undergo the Cannizzaro reaction. However, the $CC{l}_3$ group is an excellent leaving group, so in strong base (NaOH), the Haloform cleavage predominates.

$CC{l}_{3}CHO+O{H}^{-}\to H-COOH+CC{l}_3^{-}\to CHC{l}_3+HCO{O}^{-}$

The Assertion's products ($CC{l}_{3}C{H}_{2}OH$ and $CC{l}_{3}COONa$) are incorrect for the Haloform cleavage and the Cannizzaro reaction. $\to$ Assertion is False.

Reason (R): There are no $\alpha$-H in this compound, so it can't give aldol. Chloral ($CC{l}_{3}CHO$) indeed has no $\alpha$-H. The absence of $\alpha$-H makes Aldol condensation impossible.

$\to$ Reason is True.

Final Answer: Option (D).