Question

What is the major product of each of the following reactions, assuming that one equivalent of each reagent is used in each reaction?

Short answer

a) Reactive double bond is that which forms a tertiary carbocation.

Instead of Br being the nucleophile that adds to the tertiary carbon the Pi bond can be nucleophile. in this case stable 6 member ring will be formed. this is expected to be minor product because unlike the publication of the carbocation with Br bond breaking is required to form the product.

b) The double bond is more reactive than the triple bond the reaction forms a new asymmetric centre so a pair of an enantiomer is formed.

It is unlikely that the triple bond will act as a nucleophile because it would have to form an unstable vinylic cation intermediate.

c) The more reactive double bond is the one that forms a tertiary carbocation.

Step-by-step solution

How reaction proceed

a) Reactive double bond is that which forms a tertiary carbocation.

Instead of Br being the nucleophile that adds to the tertiary carbon the Pi bond can be nucleophile. in this case stable 6 member ring will be formed. this is expected to be minor product because unlike the publication of the carbocation with Br bond breaking is required to form the product.

b) The double bond is more reactive than the triple bond the reaction forms a new asymmetric centre so a pair of an enantiomer is formed.

It is unlikely that the triple bond will act as a nucleophile because it would have to form an unstable vinylic cation intermediate.

c) The more reactive double bond is the one that forms a tertiary carbocation.

Final answer