question_answer

Under\[{{S}_{N}}1\] conditions   the hydrolysis o neo-pentyl bromide gives

A) \[C{{H}_{3}}-\underset{\begin{smallmatrix}  | \\  C{{H}_{3}} \end{smallmatrix}}{\mathop{C}}\,=CH-C{{H}_{2}}OH\]

B) \[C{{H}_{3}}-\underset{\begin{smallmatrix}  | \\  OH \end{smallmatrix}}{\overset{\begin{smallmatrix}  C{{H}_{3}} \\  | \end{smallmatrix}}{\mathop{C}}}\,-C{{H}_{2}}C{{H}_{3}}\]

C) \[C{{H}_{3}}-\underset{\begin{smallmatrix}  | \\  C{{H}_{3}} \end{smallmatrix}}{\overset{\begin{smallmatrix}  C{{H}_{3}} \\  | \end{smallmatrix}}{\mathop{C}}}\,-C{{H}_{2}}OH\]

D)  None of the above

Correct Answer: B

Solution :

  \[\xrightarrow[{}]{1,2-Me\,shift}C{{H}_{3}}-\underset{\begin{smallmatrix}  ({{3}^{o}})carbocation\, \\  (more\,stable) \end{smallmatrix}}{\mathop{\underset{\oplus }{\overset{\begin{smallmatrix}  C{{H}_{3}} \\  | \end{smallmatrix}}{\mathop{C}}}\,\overset{\begin{smallmatrix}  C{{H}_{3}} \\  | \end{smallmatrix}}{\mathop{-C{{H}_{2}}}}\,}}\,\] \[\xrightarrow[{}]{O{{H}^{-}}}C{{H}_{3}}-\underset{\begin{smallmatrix}  ({{3}^{o}})carbocation\, \\  (more\,stable) \end{smallmatrix}}{\mathop{\underset{\oplus }{\overset{\begin{smallmatrix}  C{{H}_{3}} \\  | \end{smallmatrix}}{\mathop{C}}}\,\overset{\begin{smallmatrix}  C{{H}_{3}} \\  | \end{smallmatrix}}{\mathop{-C{{H}_{2}}}}\,}}\,\] \[\xrightarrow[{}]{O{{H}^{-}}}C{{H}_{3}}-\underset{\begin{smallmatrix}  | \\  OH \end{smallmatrix}}{\overset{\begin{smallmatrix}  C{{H}_{3}} \\  | \end{smallmatrix}}{\mathop{C}}}\,-C{{H}_{2}}C{{H}_{3}}\]