Understanding the Reaction and Identifying Compound 'B'

This question involves a chemical reaction sequence where compound 'B' needs to be identified. The initial compound reacts with CH₃MgBr (a Grignard reagent) followed by hydrolysis, which typically indicates nucleophilic addition to a carbonyl group.

Step 1: Analyze the Starting Compound

The starting compound is a cyclic ester (lactone). Based on common reactions:

Grignard reagents add to esters to form tertiary alcohols after hydrolysis
The reaction follows: RCOOR' + 2R"MgBr → R-C(R")₂OH after hydrolysis

Step 2: Predict the Reaction Mechanism

With CH₃MgBr (2 equivalents):

$Lactone + 2 CH {MgBr}_{3} \to Tertiary alcohol$

Step 3: Identify the Correct Structure

The correct product 'B' should be a tertiary alcohol with two methyl groups from the Grignard reagent. Among the options, the second structure shows a tertiary alcohol with appropriate substitution pattern.

Final Answer

The correct compound 'B' is the second option: Tertiary alcohol structure

Related Topics

Grignard Reactions with Carbonyl Compounds
Nucleophilic Addition to Esters
Lactone Chemistry
Tertiary Alcohol Formation

Important Formulae and Theory

General Reaction: Ester + 2RMgX → Tertiary alcohol after hydrolysis

Mechanism: Nucleophilic addition followed by elimination, then second addition

Key Point: Grignard reagents add twice to esters but only once to aldehydes/ketones