JEE PYQ: Hydrocarbons Question 31
Question 31 - 2019 (12 Apr Shift 1)
But-2-ene on reaction with alkaline $\text{KMnO}_4$ at elevated temperature followed by acidification will give:
(1) $\text{CH}_3-\text{CH}(-\text{OH})-\text{CH}(-\text{OH})-\text{CH}_3$ (diol)
(2) one molecule of $\text{CH}_3\text{CHO}$ and one molecule of $\text{CH}_3\text{COOH}$
(3) 2 molecules of $\text{CH}_3\text{COOH}$
(4) 2 molecules of $\text{CH}_3\text{CHO}$
Show Answer
Answer: (3)
Solution
$\text{CH}_3-\text{CH}=\text{CH}-\text{CH}_3 \xrightarrow{\text{KMnO}_4/\text{OH}^-,\Delta} 2\text{CH}_3\text{COOH}$. Alkaline $\text{KMnO}_4$ at elevated temperature causes oxidative cleavage of the double bond.
BETA
