Question

Identify the major product 'P' in the following sequence of reactions: $... \xrightarrow{O_3, Zn/H_2O} \xrightarrow{dil NaOH} P$.

• A. Product 1
• B. Product 2
• C. Product 3
• D. Product 4

Hint:

Aldol condensation is the standard pathway for forming carbon-carbon bonds using aldehydes/ketones.

Answer 1

The Correct Option is B

Step 1: Read the reagents.
The sequence uses $O_3$ then $Zn/H_2O$, followed by dilute NaOH. These two stages each do a well known job.

Step 2: Understand the ozonolysis step.
$O_3$ followed by $Zn/H_2O$ is reductive ozonolysis. It cuts the carbon to carbon double bond of an alkene and turns each end into a carbonyl group, giving aldehydes or ketones.

Step 3: Find the carbonyl product.
So the starting alkene is broken at the double bond, producing carbonyl compounds that carry alpha hydrogen atoms.

Step 4: Understand the dilute NaOH step.
Dilute NaOH on an aldehyde that has alpha hydrogens triggers an aldol reaction. One molecule attacks another to form a beta hydroxy carbonyl compound.

Step 5: Build the aldol product.
The carbonyl compound from ozonolysis undergoes this aldol step, joining two units to give the beta hydroxy aldehyde product.

Step 6: Match with the choices.
This aldol product matches Product 2.
\[ \boxed{\text{Product 2}} \]