Carboxylic Acids and their Derivatives 2 Question 41
41. A hydrocarbon $A$ of the formula $\mathrm{C}{8} \mathrm{H}{10}$, on ozonolysis gives compound $B\left(\mathrm{C}{4} \mathrm{H}{6} \mathrm{O}{2}\right)$ only. The compound $B$ can also be obtained from the alkyl bromide $C\left(\mathrm{C}{3} \mathrm{H}_{5} \mathrm{Br}\right)$ upon treatment with magnesium in dry ether, followed by carbon dioxide and acidification. Identify $A, B$ and $C$ and also give equations for the reactions.
(1996, 3M)
Show Answer
Solution:
- $B$ is $\mathrm{C}{3} \mathrm{H}{5} \mathrm{COOH}$ and $A$ is $\mathrm{C}{3} \mathrm{H}{5}-\mathrm{C} \equiv \mathrm{C}-\mathrm{C}{3} \mathrm{H}{5}$
Also $A$ on ozonolysis gives $B$ indicates that there is no olefinic bond in $\mathrm{C}{3} \mathrm{H}{5}$-unit of $A$ and it is cyclopropyl group.
$$ \begin{array}{ll} \Rightarrow & A=\Longrightarrow \mathrm{C}=\mathrm{C}-\square \ & B=\Longrightarrow \mathrm{COOH} \ \text { and } & C=\Longrightarrow \mathrm{Br} \end{array} $$
