Question

The number of products obtained in the following reaction is: Reaction:

• A. 1
• B. 3
• C. 2
• D. 4

Hint:

$\textbf{Key observations:}$
1. Secondary alcohols can undergo both oxidation and elimination
2. Base promotes β-elimination in benzylic alcohols
3. Heating drives both reactions forward
4. No rearrangement products expected in this case

Answer 1

The Correct Option is C

The given reaction involves the base-catalyzed (NaOH) decomposition of 1-phenylethanol (Ph-CH(OH)-CH$_3$) under heating ($\Delta$). This leads to two main products through different pathways: 
Product 1: Acetophenone (Ph-CO-CH$_3$)
- Formed via oxidation of the alcohol
- The base abstracts a proton from the -OH group
- Resulting in formation of a carbonyl group 
Product 2: Styrene (Ph-CH=CH$_2$)
- Formed via elimination reaction
- NaOH abstracts a proton from the β-carbon
- Leads to formation of a double bond Mechanistic pathways:
1. Oxidation pathway:
\[ \text{Ph-CH(OH)-CH}_3 \rightarrow \text{Ph-CO-CH}_3 \]
2. Elimination pathway:
\[ \text{Ph-CH(OH)-CH}_3 \rightarrow \text{Ph-CH=CH}_2 \] 
Why not other options?
- Only these two major products form under these conditions
- No significant side products are expected
- The reaction doesn't proceed to complete decomposition

Answer 2

The number of products obtained in the following reaction is:

Given Reaction:
The reactants are:

• Acetaldehyde (CH₃CHO)
• Phenylacetaldehyde (C₆H₅CH₂CHO)
• Under aldol condensation conditions (NaOH, heat)

Type of Reaction:
This is a classic crossed aldol condensation under basic conditions with heat. Both aldehydes have α-hydrogens and can act as both enolate donors and electrophilic acceptors. Therefore, multiple condensation products are possible.

Possible Products:
The enolate can form from either aldehyde, and attack either:

1. Self-condensation of acetaldehyde
2. Self-condensation of phenylacetaldehyde
3. Cross-condensation: acetaldehyde enolate + phenylacetaldehyde
4. Cross-condensation: phenylacetaldehyde enolate + acetaldehyde

However, due to controlled reaction conditions and heat, only the most stable condensation products remain after dehydration. Typically:

• Enolate from acetaldehyde attacking phenylacetaldehyde
• Enolate from phenylacetaldehyde attacking acetaldehyde

These give two distinct α,β-unsaturated aldehydes as major products.

Final Answer: 2