Question

The main product formed in the following reaction is: $$CH_3 - CH_2 - CH = CH_2 + HBr \longrightarrow$$

• A. 1-Bromobutane
• B. 2-Bromobutane
• C. 1-Bromo-2-methyl propane
• D. 2-Bromo-2-methyl propane

Hint:

When solving addition reactions, remember Markovnikov's rule, which tells you how the H+ and halogen (like Br) will add across the double bond. The halogen attaches to the carbon with fewer hydrogen atoms.

Answer 1

The Correct Option is B

In this reaction, the compound undergoes an electrophilic addition reaction with HBr. The reaction involves a vinyl group (C=CH2), which can undergo Markovnikov's rule for the addition of HBr. According to Markovnikov’s rule, the hydrogen will add to the carbon atom of the double bond that has the greater number of hydrogen atoms, while the bromine will add to the carbon atom that has fewer hydrogen atoms.
Thus, the addition will proceed as follows:
- The proton (H+) will add to the carbon of the double bond that has more hydrogen atoms (CH2 group).
- The bromine (Br) will add to the other carbon (CH) of the double bond.
This leads to the formation of 2-Bromobutane as the major product.