The key intermediate in the following reaction would be a vinylic carbocation. $\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\mathrm{Br}$
$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$|
$\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2}-\mathrm{C} \equiv \mathrm{C}-\mathrm{H}$$\underset{\mathrm{CH}_{3} \mathrm{COOH}}{\stackrel{\mathrm{HBr}}{\longrightarrow}}$$\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2}-\mathrm{C}=\mathrm{CH}_{2}$

Question

Quizplus · Accepted Answer

The reaction proceeds via electrophilic addition of HBr to the alkyne to form a vinylic carbocation, which is then deprotonated to give the alkene product.

The Key Intermediate in the Following Reaction Would Be a Vinylic