Which of the following is the correct IUPAC name ?

Options

A. 3-ethyl-4, 4-dimethylheptane
B. 4, 4-dimethyl-3-ethylheptane
C. 5-ethyl-4, 4-dimethylheptane
D. 4, 4-bis(methyl)-3-ethylheptane

Explanation

To determine the correct IUPAC name from the given options, we need to follow the systematic approach of naming organic compounds according to IUPAC rules. Here’s a step-by-step solution:

### Step-by-Step Solution:

1. **Identify the Longest Carbon Chain:**
- The longest continuous carbon chain must be identified first. In this case, we are dealing with heptane, which indicates a chain of 7 carbon atoms.

2. **Number the Carbon Chain:**
- Number the carbon atoms in the chain starting from the end nearest to the first substituent. This ensures that the substituents have the lowest possible numbers.

3. **Identify and Name the Substituents:**
- In the options given, we have ethyl and dimethyl groups as substituents.
- For example, in the name "3-ethyl-4,4-dimethyl-heptane":
- The ethyl group is at the 3rd carbon.
- There are two methyl groups at the 4th carbon.

4. **Write the Name in Correct Order:**
- When writing the name, substituents should be listed in alphabetical order regardless of their position.
- "Ethyl" comes before "dimethyl" alphabetically.

5. **Evaluate Each Option:**
- **Option A: 3-ethyl-4,4-dimethyl-heptane**
- Correct: Ethyl (E) at position 3 and dimethyl (D) at position 4.
- **Option B: 4,4-dimethyl-3-ethyl-heptane**
- Incorrect: Ethyl should come before dimethyl in the name.
- **Option C: 5-ethyl-4,4-dimethyl-heptane**
- Correct: Ethyl (E) at position 5 and dimethyl (D) at position 4.
- **Option D: 4-4-bis-methyl-heptane**
- Incorrect: The term "bis" is not appropriate here as it is used in specific cases for complex ligands.

6. **Conclusion:**
- The correct IUPAC names from the options provided are **Option A** and **Option C**.