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 will follow these steps:

### Step 1: Identify the Parent Chain
- The parent chain is the longest continuous chain of carbon atoms. In this case, we are looking for a chain of 7 carbon atoms, which corresponds to "heptane."

### Step 2: Identify the Substituents
- The substituents are groups attached to the parent chain. In the options provided, we have ethyl (C2H5) and methyl (C1H3) groups as substituents.

### Step 3: Number the Carbon Chain
- Number the carbon atoms in the parent chain from one end to the other. The goal is to give the substituents the lowest possible numbers.

### Step 4: Assign Locants to Substituents
- Based on the numbering, assign locants (numbers) to each substituent. For example, if an ethyl group is on the third carbon and a methyl group is on the fourth carbon, we would write it as 3-ethyl-4-methyl.

### Step 5: Alphabetical Order of Substituents
- When writing the IUPAC name, substituents should be listed in alphabetical order regardless of their locants. For example, "ethyl" comes before "methyl."

### Step 6: Construct the IUPAC Name
- Combine the locants, substituent names, and the parent chain name to form the complete IUPAC name.

### Step 7: Evaluate Each Option
- Compare the constructed name with the provided options to identify the correct one.

### Conclusion
After analyzing the structure and substituents, the correct IUPAC name is **3-ethyl-4,4-dimethylheptane**.