Question

For the given reaction :
$R\underset{\left(ii\right)H_{2}O}{\overset{\left(i\right)O_3}{\to }}\text{Only one product}$

Here R can be :

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

Symmetrical alkynes on ozonolysis give single product.
Here, compound (b) 3-Hexyne is an symmetrical alkyne whereas compound (a), (c) and (d) are unsymmetrical alkenees so they give two different products.

The alkynes react with ozone to form ozonides. These ozonides decompose, when reacted with water in the presence of Zn, to give diketones.
In the absence of Zn, ozonolysis followed by hydrolysis produces acid.

Here, 3-Hexyne react with $O_3$ to form peroxy linkage derivative called ozonide. Due to the absence of Zn, the ozonide undergoes hydrolysis to form 2 mole of propanoic acid.

Compound (a) gives acetic acid and Butanoic acid on ozonolysis.
Compound (c) gives acetic acid and Pentanoic acid on ozonolysis.
Compound (d) gives propanoic acid and Butanoic acid on ozonolysis.