Question

An alkene, \(\mathrm{C_3H_6}\) (X), on treatment with HBr in presence of peroxide gives (Y). The compound (Y) on treatment with \(\mathrm{AgNO_2}\) in ethanol gives (Z). The compounds (X), (Y) and (Z) are respectively

• A. propene, 1-bromopropane, 1-nitropropane
• B. propene, 2-bromopropane, 2-nitropropane
• C. propene, 2-bromopropane, 1-nitropropane
• D. propyne, 1-bromopropane, 1-nitropropane
• E. propene, 1,2-dibromopropane, 1,2-dinitropropane

Hint:

Remember: - Peroxide $\Rightarrow$ anti-Markovnikov addition - $\mathrm{AgNO_2}$ $\Rightarrow$ nitro compound (not nitrite)

Answer 1

The Correct Option is A

Concept:
• HBr + peroxide $\rightarrow$ anti-Markovnikov addition
• $\mathrm{AgNO_2}$ gives nitro compounds ($\mathrm{-NO_2}$)

Step 1: Identify alkene (X).
\[ \mathrm{C_3H_6} \Rightarrow \text{propene} \]

Step 2: Addition of HBr (peroxide effect).
\[ \mathrm{CH_3-CH=CH_2 \xrightarrow{HBr/peroxide} CH_3-CH_2-CH_2Br} \] (Y) = 1-bromopropane

Step 3: Reaction with $\mathrm{AgNO_2}$.
\[ \mathrm{CH_3-CH_2-CH_2Br \xrightarrow{AgNO_2} CH_3-CH_2-CH_2NO_2} \] (Z) = 1-nitropropane