Before You Begin
Question #44379
The Question
An alkene, \ce{3,3-dimethyl-1-butene}, is subjected to an alkoxymercuration-demercuration sequence. It is first reacted with \ce{Hg(OAc)2} in excess \ce{CH3OD}. The resulting organomercury intermediate is subsequently reduced using \ce{NaBD4} in aqueous \ce{NaOH}. Which of the following represents the major organic product formed?
Options
- A.
\ce{(CH3)3C-CH(OCH3)-CH2D}
- B.
\ce{(CH3)2C(OCH3)-CH(CH3)-CH2D}
- C.
\ce{(CH3)3C-CH(OD)-CH2D}
- D.
\ce{(CH3)3C-CH(OCH3)-CH3}
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
Oxymercuration-Demercuration Specificity|Ether Cleavage Patterns
Why This Question Is Tricky
Common Mistakes
This question tests three critical mechanistic traps: 1) Solvent Participation: Recognizing that in non-aqueous conditions, the solvent (\ce{CH3OD}) acts as the nucleophile, forming an ether rather than an alcohol. 2) Isotope Tracking in the Nucleophile: Understanding that \ce{CH3OD} attacks via the oxygen atom, and subsequent deprotonation removes the \ce{D+}, leaving an \ce{-OCH3} group (not \ce{-OD}). 3) Isotope Tracking in Reduction: Knowing that the atom added during the demercuration step comes strictly from the borohydride reagent (\ce{NaBD4}), placing a D at the terminal carbon.
It also reinforces that mercurinium ions do not undergo 1,2-alkyl shifts.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Alcohols, Phenols, and Ethers - Class 12 |
| Concept | Oxymercuration-Demercuration Specificity |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |