Question

What is the major product Z in the given reaction sequence?

• A. 1-Bromo-2-methylpropene
• B. 2-Methoxy-2-methylbutane
• C. 2-Bromo-3-methylbutane
• D. 1-Bromo-2-methylbutane

Hint:

Grignard reagents add to the carbonyl group, leading to alcohol formation. With \(\text{HBr}\), the alcohol undergoes substitution, and heat induces an elimination to form alkenes.

Answer 1

The Correct Option is C

The given reaction involves a Grignard reagent (\(\text{C}_2\text{H}_5\text{MgBr}\)) reacting with acetone (\(\text{(CH}_3\text{)}_2\text{C=O}\)) to form an alcohol (\(X\)). The alcohol undergoes a substitution reaction with hydrogen bromide (\(\text{HBr}\)) to form a bromoalkane. The final step involves heating with copper at 573 K, which leads to the formation of an alkene. The major product is 2-Bromo-3-methylbutane. Hence, the correct answer is (3) 2-Bromo-3-methylbutane