COMEDK · Chemistry · 26. Alcohols Phenols and Ethers

Identify \([\mathrm{X}]\) used in the given reaction.
\([\mathrm{X}]+\) Copper \(/ 573 \mathrm{~K} \rightarrow[\mathrm{Y}]\)
\([\mathrm{Y}] \xrightarrow[\text { (ii) } \mathrm{H}_2 \mathrm{O} / \mathrm{H}^{+}]{\text {(i) } \mathrm{CH}_3 \mathrm{MgBr}}\) Tert.butyl alcohol. (major product)

A Butan-1-ol
B Butan-2-ol
C Propan-1-ol
D Propan-2-ol

Verified Solution

Answer & Solution

Correct Answer

(D) Propan-2-ol

Step-by-step Solution

Detailed explanation

The reaction of \([\mathrm{Y}]\) with \(\mathrm{CH}_3\mathrm{MgBr}\) followed by hydrolysis yields tert-butyl alcohol, which is 2-methylpropan-2-ol. This indicates that \([\mathrm{Y}]\) must be acetone (propanone), as the Grignard reaction of acetone with methylmagnesium bromide…

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

Same subject

Match reactions in Column I with the corresponding products formed as given in Column II.

Column I	Column II
A. \(\text{C}_6\text{H}_5\text{N}_2^+\ \text{Cl}^- + \dfrac{\text{H}_2\text{O}}{warm} \rightarrow\)	P. p–Bromophenol
B. \(\text{C}_6\text{H}_5\text{OH} + \dfrac{\text{Br}_2\ \text{in}\ \text{CS}_2}{273K} \rightarrow\)	Q. 2,4,6–Tribromophenol
C. \(\text{C}_6\text{H}_5\text{OH} + \dfrac{(i)\ \text{CHCl}_3 + \text{NaOH}(aq)}{(ii)\ \text{HCl}} \rightarrow\)	R. Phenol
D. \(\text{C}_6\text{H}_5\text{OH} + \text{Br}_2\ (aq) \rightarrow\)	S. 2–Hydroxybenzaldehyde

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Identify \([\mathrm{X}]\) used in the given reaction.\([\mathrm{X}]+\) Copper \(/ 573 \mathrm{~K} \rightarrow[\mathrm{Y}]\)\([\mathrm{Y}] \xrightarrow[\text { (ii) } \mathrm{H}_2 \mathrm{O} / \mathrm{H}^{+}]{\text {(i) } \mathrm{CH}_3 \mathrm{MgBr}}\) Tert.butyl alcohol. (major product)

Step-by-step Solution

Identify \([\mathrm{X}]\) used in the given reaction.
\([\mathrm{X}]+\) Copper \(/ 573 \mathrm{~K} \rightarrow[\mathrm{Y}]\)
\([\mathrm{Y}] \xrightarrow[\text { (ii) } \mathrm{H}_2 \mathrm{O} / \mathrm{H}^{+}]{\text {(i) } \mathrm{CH}_3 \mathrm{MgBr}}\) Tert.butyl alcohol. (major product)