Question

• A.
• B.
• C.
• D.

Hint:

When dealing with elimination and reduction reactions, it's essential to understand how the reagents affect the intermediates and lead to the final product. Alcohol formation and reduction are key steps in this type of organic transformation.

Answer 1

The Correct Option is D

The reactions proceed as follows:

Step 1: In the first step, \(\text{KOH (alc.)}\) induces an elimination reaction, which removes a bromine atom from the carbon chain, resulting in the formation of cyclooctene (a 8-membered ring with a double bond).

Step 2: The second step with \(\text{NaNH}_2\) induces further elimination, removing another hydrogen atom from the carbon-carbon single bonds (a step leading to the formation of cyclooctyne, a 8-membered ring with a triple bond).

Step 3: The reaction with \(\text{Hg}^{2+}/\text{H}^{+}\) induces hydromercuration of the alkyne, resulting in the addition of a mercury ion to the carbon-carbon triple bond.
This creates an alkene intermediate.

Step 4: Finally, the Clemmensen reduction with \(\text{Zn-Hg} / \text{H}^{+}\) reduces the alkene to a fully saturated ring, cyclooctane, which is the final product.
This reaction removes the double bond and saturates the 8-membered ring.