Question

Electrophilic addition reactions proceed in two steps. The first step involves the addition of an electrophile. Name the type of intermediate formed in the first step of the following addition reaction.

H₃C—HC = CH₂ + H⁺ →?

(i) 2° Carbanion

(ii) 1° Carbocation

(iii) 2° Carbocation

(iv) 1° Carbanion

Answer 1

(iii) When the electrophile attacks CH₃ - CH = CH₂, delocalisation of electrons can take place in two possible ways .

As 2° carbocation is more stable than 1° carbocation, the first addition is more feasible.