Consider the following reaction , `H_3C-undersetundersetD|CH-undersetunderset(CH_3)|CH-CH_3+oversetdot(Br) to 'X' + HBr `
Identify the structure of the major product 'X'

Options

A. `CH_3-undersetundersetD|CH-undersetunderset(CH_3)|CH-oversetdot(CH_2)`
B. `CH_3-undersetunderset(D)|CH-undersetunderset(CH_3)|dotC-CH_3`
C. `CH_3-undersetunderset(D)|dotC-undersetunderset(CH_3)|CH-CH_3`
D. `CH_3-oversetdot(CH)-undersetunderset(CH_3)|CH-CH_3`

Explanation

To identify the structure of the major product 'X' from the given reaction, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactant is an alkene with the structure:
\[ H_3C - \underset{\text{D}}{C} - \underset{\text{(CH}_3\text{)}}{C} - CH - CH_3 \]
This indicates that we have a substituted alkene where one carbon has a deuterium (D) atom.

2. **Understand the Reaction**: The reaction involves the addition of bromine (Br) to the alkene. This is an electrophilic addition reaction where bromine adds across the double bond.

3. **Determine the Site of Bromine Addition**: The bromine will add to the less substituted carbon of the double bond due to Markovnikov's rule. In this case, the double bond is between the carbon with deuterium and the carbon attached to the methyl group (CH3).

4. **Formation of the Major Product**: When bromine adds to the double bond, it will replace the hydrogen (H) atom on the less substituted carbon (the carbon with deuterium). The reaction can be visualized as:
\[ H_3C - C - C - CH - CH_3 + Br_2 \rightarrow H_3C - C - C - Br - CH_3 + HBr \]
This results in the formation of a bromoalkane.

5. **Write the Structure of Product 'X'**: The major product 'X' will have the following structure:
\[ H_3C - C - C - Br - CH_3 \]
This indicates that bromine has been added to the carbon that was originally bonded to hydrogen.

6. **Final Structure Confirmation**: The final structure of the major product 'X' can be confirmed as:
\[ \text{Br} - H_3C - C - CH_3 - CH_3 \]

### Conclusion:
The major product 'X' is a bromoalkane with the structure:
\[ H_3C - C(Br) - CH_3 - CH_3 \]