Question

What is the major product of each of the following reactions?

Short answer

In this markoniv addition takes place.

Markoniv addition= Positive ion will go to that double bonded carbon which has more no of hydrogens attached and negative ion will go towards that carbon which has less number of hydrogens attached.

Step-by-step solution

Step 1: How the reaction proceed

In this markoniv addition takes place.

Markoniv addition= Positive ion will go to that double bonded carbon which has more no of hydrogens attached and negative ion will go towards that carbon which has less number of hydrogens attached.

Final answer

a) Here markoniv addition takes place.So Br^- attached with that carbon which has less number of hydrogen atoms and H⁺ attached with that carbon which has more number of hydrogen atoms.

b) Here markoniv addition takes place.So Br^- attached with that carbon which has less number of hydrogen atoms and H⁺ attached with that carbon which has more number of hydrogen atoms. As here we use excess HBr so first it make double bond then double bond also breaks and form single bond and do markoniv addition.

c) Here Br₂ dissociate as Br^- and Br⁺ and markoniv addition takes place.

d) Here Br₂ dissociate as Br^- and Br⁺ and markoniv addition takes place. As here we use excess Br₂ so first it make double bond then double bond also breaks and form single bond and do markoniv addition.

e) Here markoniv addition takes place.So Br^- attached with that carbon which has less number of hydrogen atoms and H⁺ attached with that carbon which has more number of hydrogen atoms. As here we use excess HBr so first it make double bond then double bond also breaks and form single bond and do markoniv addition.

f) As this is unsymmetrical alkyne so two products will form. Here markoniv addition takes place.So Br^- attached with that carbon which has less number of hydrogen atoms and H⁺ attached with that carbon which has more number of hydrogen atoms. As here we use excess HBr so first it make double bond then double bond also breaks and form single bond and do markoniv addition.