Which of the following is tertiary bromide?

Options

A. 1 bromo-2, 2-dimethylpropane
B. 1-bromo-I, 1-dimethylbutane
C. 1 bromo-2, 3-methylbutane
D. 1 bromo-2, 3-methylbutane

Answer

To determine which of the given compounds is a tertiary bromide, we need to identify the structure of each compound and check the carbon to which the bromine atom is attached. A tertiary bromide is defined as a compound where the bromine is attached to a tertiary carbon, which is a carbon atom bonded to three other carbon atoms.

### Step-by-Step Solution:

1. **Understand the Definition of Tertiary Bromide**:
- A tertiary bromide has bromine attached to a tertiary carbon, which is a carbon atom bonded to three other carbon atoms.

2. **Analyze the Options**:
- We will examine each option to see where the bromine is attached.

3. **Option 1: 1-bromo-2,2-dimethylpropane**:
- Structure: CH3-CHBr-CH(CH3)2
- In this structure, the bromine is attached to a primary carbon (the second carbon is attached to only one other carbon).
- **Conclusion**: This is a primary bromide.

4. **Option 2: 1-bromo-1,1-dimethylbutane**:
- Structure: (CH3)3C-Br
- In this structure, the bromine is attached to a carbon that is bonded to three other carbon atoms (the three methyl groups).
- **Conclusion**: This is a tertiary bromide.

5. **Option 3: 1-bromo-2,3-dimethylbutane**:
- Structure: CH3-CHBr-CH(CH3)-CH3
- In this structure, the bromine is attached to a secondary carbon (the second carbon is attached to two other carbons).
- **Conclusion**: This is a secondary bromide.

6. **Option 4: 1-bromo-2,3-dimethylbutane**:
- Structure: CH3-CH(CH3)-CHBr-CH3
- In this structure, the bromine is attached to a secondary carbon (the carbon with bromine is attached to two other carbons).
- **Conclusion**: This is also a secondary bromide.

### Final Answer:
The compound that is a tertiary bromide is **Option 2: 1-bromo-1,1-dimethylbutane**.