Question

Identify the product 'B' in the following reaction sequence.

$C_2H_5-Br \xrightarrow[Dry ether]{Mg} A \xrightarrow{CH_3OH} B$

• A. $H_3C-CH_2-CH_3$
• B. $C_2H_5-O-CH_3$
• C. $C_2H_6$
• D. $C_2H_5-OH$

Answer 1

Answer: (C)

$C_2H_6$

Answer 2

1. Formation of Grignard Reagent:

   $$\text{C}_2\text{H}_5\text{-Br} + \text{Mg} \xrightarrow{\text{dry ether}} \text{C}_2\text{H}_5\text{MgBr} \quad \text{(Product A)}$$

2. Reaction with Methanol:

   The Grignard reagent, being strongly basic, reacts with methanol ($CH_3OH$) by abstracting a proton:

   $$\text{C}_2\text{H}_5\text{MgBr} + \text{CH}_3\text{OH} \rightarrow \text{C}_2\text{H}_6 + \text{MgBrOCH}_3$$

   Thus, product B is ethane ($C_2H_6$).