Question

'R formed in the following sequence of reactions is :

• A.
• B.
• C.
• D.

Answer 1

The Correct Option is A

To determine the compound 'R' formed from the given sequence of reactions, we need to analyze each step carefully:

1. Reaction with NaCN:

The initial compound is an acyl halide. Reaction with \(\text{NaCN}\) in the presence of acetic acid (\(\text{HOAc}\)) will lead to a nucleophilic attack by the cyanide ion on the carbonyl carbon, resulting in the formation of a cyanohydrin, which we refer to as 'P'.

1. Hydrolysis to Alcohol:

The next reaction involves treating 'P' with acidified ethanol (\(\text{EtOH/H}^+\)), which converts the cyanide group to an ester 'Q' by nucleophilic substitution and acid-catalyzed hydrolysis.

1. Grignard Reaction:

Compound 'Q' is then treated with two equivalents of methyl magnesium bromide (\(2\text{MeMgBr}\)), followed by aqueous acid workup (\(\text{H}_3\text{O}^+\)). This Grignard reaction occurs at the ester carbonyl, forming a tertiary alcohol 'R' after the addition of two methyl groups.

Based on this analysis, the major product 'R' is a tertiary alcohol with two additional methyl groups attached to the formerly carbonyl carbon.

This image shows the structural formula of compound 'R'. This is consistent with the reaction pathway described above.

Conclusion: The correct product \( R \) matches Option (1).