Hydrocarbons 2 Question 41
43. The major compound $Y$ is (a)
(c)
(b)
(d)
Passage 2
An acyclic hydrocarbon $P$, having molecular formula $\mathrm{C}{6} \mathrm{H}{10}$, gave acetone as the only organic product through the following sequence of reactions, in which $Q$ is an intermediate organic compound.
$$ \underset{\left(\mathrm{C}{6} \mathrm{H}{10}\right)}{P} \xrightarrow[\substack{\text { (ii) } \mathrm{NaBH}{4} / \text { ethanol } \ \text { (iii) dil. acid }}]{\text { (i) dil. } \mathrm{H}{2} \mathrm{SO}{4} / \mathrm{HgSO}{4}} $$
(2011)
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Answer:
Correct Answer: 43. (a)
Solution:
Passage 2
The final ozonolysis product indicates that the alkene before ozonolysis is
Also $P\left(\mathrm{C}{6} \mathrm{H}{10}\right)$ has two degree of unsaturation and oxymercuration demercuration hydration indicates that it is an alkyne. As alkyne, on hydration, gives a carbonyl compound which on reduction with $\mathrm{NaBH}_{4}$ gives a $2^{\circ}$ alcohol.
$-\mathrm{C} \equiv \mathrm{C}-+\mathrm{H}{2} \mathrm{O} \longrightarrow \stackrel{\stackrel{\mathrm{O}}{\mathrm{C}}-\mathrm{CH}{2}-}{\text { (i) } \mathrm{NaBH}{4}} \underset{\text { (ii) } \mathrm{H}^{+}}{\underset{\mathrm{H}}{\mathrm{C}}-\left.\right|{2^{\circ} \text { alcohol }} ^{\mathrm{OH}}-\mathrm{CH}_{2}-}$
The secondary alcohol that can give above shown alkene on acid catalysed dehydration is
