Question

Complete the following reactions by writing the structural formulae of ‘A’ and ‘B’:

(i) \( \text{CH}_3\text{CH} = \text{CH}_2 \)
\( \xrightarrow{\text{HBr, Peroxide}} \) ‘A’ \( \xrightarrow{\text{aq. KOH}} \) ‘B’

(ii) \( \text{CH}_3\text{CH}_2\text{CH(Cl)CH}_3 \)
\( \xrightarrow{\text{alc. KOH}, \Delta} \) ‘A’ \( \xrightarrow{\text{HBr}} \) ‘B’

(iii) ‘A’ \( \xrightarrow{\text{Mg}} \) \( \text{CH}_3\text{CH}_2\text{CH}_2\text{MgCl} \) \( \xrightarrow{\text{H}_2\text{O, H}^+} \) ‘B’ (Main product)

Hint:

In peroxide conditions, HBr adds via anti-Markovnikov rule. Grignard reagents form alkanes with protonation.

Answer 1

Complete the following reactions by writing the structural formulae of ‘A’ and ‘B’:

(i) \( \text{CH}_3\text{CH} = \text{CH}_2 + \text{HBr (Peroxide)} \) \( \xrightarrow{} \) \( \text{CH}_3\text{CH}_2\text{CH}_2\text{Br} \) (‘A’) \( \xrightarrow{\text{aq. KOH}} \) \( \text{CH}_3\text{CH}_2\text{CH}_2\text{OH} \) (‘B’)

(ii) \( \text{CH}_3\text{CH}_2\text{CH(Cl)CH}_3 + \text{alc. KOH} \) \( \xrightarrow{} \) \( \text{CH}_3\text{CH} = \text{CH}\text{CH}_3 \) (‘A’) \( \xrightarrow{\text{HBr}} \) \( \text{CH}_3\text{CHBrCH}_2\text{CH}_3 \) (‘B’)

(iii) \( \text{CH}_3\text{CH}_2\text{CH}_2\text{Br} \) (‘A’) \( + \text{Mg} \) \( \xrightarrow{} \) \( \text{CH}_3\text{CH}_2\text{CH}_2\text{MgBr} \) \( \xrightarrow{\text{H}_2\text{O}/\text{H}^+} \) \( \text{CH}_3\text{CH}_2\text{CH}_3 \) (‘B’)