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Question #44388

Difficulty: 8/10 | 🟢 Free

The Question

Consider the following reaction sequence starting from 2,6-dimethylphenol: 2,6-Dimethylphenol→298 K\ceCrO2Cl2 (2 eq), \ceCS2A\text{2,6-Dimethylphenol} \xrightarrow[\text{298 K}]{\ce{CrO2Cl2} \text{ (2 eq), } \ce{CS2}} \mathbf{A} A→\ceNaBH4, EtOHB\mathbf{A} \xrightarrow{\ce{NaBH4}, \text{ EtOH}} \mathbf{B} B→\ceNaH (excess), \ceCH3I (excess), THFC\mathbf{B} \xrightarrow{\ce{NaH} \text{ (excess), } \ce{CH3I} \text{ (excess), THF}} \mathbf{C} C→hν\ceNBS (1 eq), \ceCCl4D (Major Product)\mathbf{C} \xrightarrow[\text{h}\nu]{\ce{NBS} \text{ (1 eq), } \ce{CCl4}} \mathbf{D} \text{ (Major Product)} Identify the correct IUPAC name of the final major product D\mathbf{D}.

Options

  • A.

    2-(bromomethyl)-1,4-dimethoxy-6-methylbenzene

  • B.

    1-(bromomethyl)-2-methoxy-3-(methoxymethyl)benzene

  • C.

    2-(bromomethyl)-4-chloro-1-methoxy-6-methylbenzene

  • D.

    3-bromo-1,4-dimethoxy-2,6-dimethylbenzene

Check Your Answer

Correct Answer

Step-by-Step Solution

Explanation

How the Examiner Thinks

Exception_Exposure

Learn to identify edge cases and boundary exceptions that JEE examiners hide in math problems.

Concepts Behind This Question

EAS in Phenols|Oxidation State Traps|Reduction Selectivity (Sn/HCl vs LiAlH4)

Why This Question Is Tricky

Common Mistakes

The core trap tests the student's ability to recognize the 'Oxidation State Trap' in highly activated aromatic systems.

Students mechanically apply the Etard reaction (\ceCrO2Cl2\ce{CrO2Cl2}) to the benzylic methyl groups, falsely identifying A\mathbf{A} as a benzaldehyde derivative (leading to Option B).

Alternatively, they assume standard Electrophilic Aromatic Substitution (chlorination, leading to Option C).

The hidden variable is the competitive oxidation rate (kox>ksubk_{ox} > k_{sub}), where the electrophilic oxidant preferentially attacks the electron-rich phenolic ring to form a quinone, completely altering the subsequent reaction pathway.

Quick Facts About This Question

Question Information

SubjectChemistry
ChapterAlcohols, Phenols, and Ethers - Class 12
ConceptEAS in Phenols
Difficulty8
Cognitive Load7
Target Solve Time160 sec
AccessFree