Question

Toluene \( \xrightarrow{(1) \text{CrO}_2\text{Cl}_2 / \text{CS}_2} \xrightarrow{(2) \text{H}_3\text{O}^+} \text{X} \xrightarrow[\text{Conc. NaOH}]{50\%} \text{Y} + \text{Z} \)
The correct statements about X, Y, and Z are
A. Y is a secondary alcohol
B. Y is the reduction product of X
C. Z on heating with soda lime gives benzene
D. Y does not give \( \text{H}_2 \) gas with Na metal

• A. B & C only
• B. A & B only
• C. A & D only
• D. B & D only

Hint:

Cannizzaro Reaction: \(2\text{Aldehyde} \xrightarrow{\text{Conc Base}} \text{Alcohol (Red)} + \text{Salt of Acid (Ox)}\).

Answer 1

The Correct Option is A

Step 1: Identify Reaction 1 (Etard Reaction):
Toluene reacts with Chromyl Chloride to form a chromium complex, which on hydrolysis yields Benzaldehyde (X). \(X = \text{C}_6\text{H}_5\text{CHO}\).
Step 2: Identify Reaction 2 (Cannizzaro Reaction):
Benzaldehyde (no \(\alpha\)-H) reacts with conc. NaOH to undergo disproportionation. Reduction product (Y): Benzyl Alcohol (\(\text{C}_6\text{H}_5\text{CH}_2\text{OH}\)). Oxidation product (Z): Sodium Benzoate (\(\text{C}_6\text{H}_5\text{COONa}\)).
Step 3: Evaluate Statements:
* A. Y is a secondary alcohol: Benzyl alcohol (\(\text{Ph-CH}_2\text{-OH}\)) is a primary alcohol. (False). * B. Y is reduction product of X: Aldehyde reduces to Alcohol. (True). * C. Z with soda lime gives benzene: Decarboxylation of Sodium Benzoate yields Benzene. \(\text{Ph-COONa} + \text{NaOH/CaO} \rightarrow \text{Ph-H}\). (True). * D. Y does not give H2 with Na: Alcohols react with Na to release hydrogen. (False). Final Answer:
Option (A).