Question

CH\(_2\) = CH\(_2\) + CH\(_2\)N\(_2\) \(\xrightarrow{\Delta}\) Intermediate in the above reaction is

• A. C\(_2\)H\(_5\)C\(_2\)H\(_5\)
• B. CH\(_3\)CH\(_2\)C\(_2\)H\(_5\)
• C. CH\(_2\)CH\(_2\)C\(_2\)H\(_2\)
• D. :CH\(_2\)

Hint:

Carbenes are highly reactive intermediates with a divalent carbon atom having two non-bonded electrons. They add to alkenes to form cyclopropanes.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Diazomethane (CH\(_2\)N\(_2\)) decomposes upon heating to produce a carbene (:CH\(_2\)).
Step 2: Detailed Explanation:}}
The reaction of ethene with diazomethane in the presence of heat or light is a carbene addition reaction. Diazomethane decomposes to form methylene carbene (:CH\(_2\)) which then adds to the double bond of ethene to form cyclopropane. \[ CH_2N_2 \xrightarrow{\Delta} :CH_2 + N_2 \] \[ :CH_2 + CH_2=CH_2 \rightarrow \text{cyclopropane} \] The intermediate is the methylene carbene.
Step 3: Final Answer:
The intermediate is :CH\(_2\) (methylene carbene), option (D).