In the addition of hydrogen bromide to alkynes in the absence of peroxides,which of the following species is believed to be an intermediate?
A)vinyl anion
B)vinyl cation
C)vinyl radical
D)carbene
E)bromonium ion

Question

Quizplus · Accepted Answer

In the addition of hydrogen bromide to alkynes, the intermediate believed to be formed is a vinyl cation. This is because the reaction proceeds through a mechanism where the alkyne first forms a protonated alkyne (a vinyl cation) before the bromide ion adds to it.

In the Addition of Hydrogen Bromide to Alkynes in the Absence