Question

$C{{H}_{3}}-CH=CH-C{{H}_{3}}+C{{H}_{2}}{{N}_{2}}\xrightarrow[\Delta ]{}A$ : A can be

Answer 1

Hint: The given reaction is between an alkene and the organic reagent diazomethane. When we treat an alkene with diazomethane, cyclopropanation reactions can occur. The reagent Diazomethane can be exposed to heat, light, or copper to enable the loss of nitrogen gas and the creation of the simplest carbene methylene.

Complete step by step solution:
- As we know, the organic reagent Diazomethane which has the molecular formula $C{{H}_{2}}{{N}_{2}}$, is an yellow, poisonous and potentially explosive compound, which exists in the gaseous state at the room temperature. The structure of diazomethane can be explained by using three resonance forms of the molecule.
- The compound $C{{H}_{3}}-CH=CH-C{{H}_{3}}$ is 2-butene. It’s an acyclic alkene with four carbon atoms. It is one of the simplest alkene molecule which exhibit cis-trans isomerism. They can exit as two geometric isomers such as cis-2-butene and trans-2-butene.
- We are asked to find the reaction between 2-butene molecule and Diazomethane on heating and the product A should be identified. When a molecule of diazomethane is added across the C=C double bond, a five membered ring in the compound is formed as in the options A and C.
- Similarly If only the methylene group present in Diazomethane is added across C=C double bond, along with liberation of nitrogen a cyclopropane derivative is obtained as compound A as in the options B and D. It should be noted that, in both cases geometric isomers of compound A are formed.

Thus, all the four options denote the possible structures for the product A therefore the correct options are (A), (B), (C) and (D).

Note: Keep in mind that the diazomethane is a highly reactive molecule. The reason is that as we are aware, every nitrogen atoms’ aim is to regain the freedom it had as a nitrogen molecule in the earth’s atmosphere. In the diazomethane molecule this freedom can be obtained simply through breaking of a single carbon-nitrogen bond and this makes diazomethane a pretty frisky little molecule and greatly reactive in a number of reactions.