Which of the following is an incorrect name according to `IUPAC?`

Options

A. `2-`Cyclopropyl butane
B. Cyclohexyl cyclohexane
C. `1-`bromo`-2,2-`dichloro cyclobutane
D. `1-`cyclobutyl cyclobutane

Explanation

To determine which of the given names is incorrect according to IUPAC nomenclature, let's analyze each option step by step.

### Step 1: Analyze Option A - Two Cyclopropyl Butane
1. **Identify the main chain**: The main chain is butane, which has four carbon atoms.
2. **Identify the substituent**: The substituent is cyclopropyl, which is a three-membered cyclic structure.
3. **Number the carbon chain**: Number the butane chain from one end to the other. The correct numbering would be:
- 1: CH3
- 2: Cyclopropyl (C3H5)
- 3: CH2
- 4: CH3
4. **Final name**: The name "two cyclopropyl butane" indicates that there is a cyclopropyl group on the second carbon of the butane chain, which is correct.

**Conclusion for Option A**: This name is correct.

### Step 2: Analyze Option B - Cyclohexyl Cyclohexane
1. **Identify the main chain**: The main chain is cyclohexane, which is a six-membered ring.
2. **Identify the substituent**: The substituent is cyclohexyl, which is also a six-membered ring.
3. **Naming issue**: The name "cyclohexyl cyclohexane" suggests that there is a cyclohexyl group attached to cyclohexane, which is redundant and not a proper IUPAC name.

**Conclusion for Option B**: This name is incorrect.

### Step 3: Analyze Option C - One Bromo Two Two Dichloro Cyclobutane
1. **Identify the main chain**: The main chain is cyclobutane, which is a four-membered ring.
2. **Identify the substituents**: The substituents are bromo (Br) and dichloro (Cl).
3. **Number the ring**: The correct way to number the ring should minimize the locants:
- If we number the ring starting from a carbon with bromo, we get:
- 1: Br
- 2: Cl
- 3: Cl
- 4: (no substituent)
4. **Locant issue**: The name "one bromo two two dichloro" implies that the chlorines are on the second carbon, but it should be "one bromo one dichloro" to minimize the locants.

**Conclusion for Option C**: This name is incorrect.

### Step 4: Analyze Option D - One Cyclobutyl Cyclobutane
1. **Identify the main chain**: The main chain is cyclobutane.
2. **Identify the substituent**: The substituent is cyclobutyl.
3. **Number the ring**: The cyclobutyl group is attached to one of the carbons in the cyclobutane ring.
4. **Final name**: The name "one cyclobutyl cyclobutane" indicates that there is a cyclobutyl group on one of the carbons of the cyclobutane, which is correct.

**Conclusion for Option D**: This name is correct.

### Final Answer
The incorrect name according to IUPAC is **Option B**: Cyclohexyl Cyclohexane.