A hydrocarbon (R) has six membered ring in which there is no unsaturation.Two alkyl group are attached to the ring adjacent
to each other.One group has 3 carbon atoms with branching at `1^(st)` carbon and another has 4 carbon atoms.The larger alkyl group has main chain of three carbon atoms of which second carbon is substituted. Correct IUPAC name of compound (R) is

Options

A. 1-(1-Methylethyl)-2-(1-methylpropyl)cyclohexane
B. 1-(2-Methylethyl)-2-(1-methylpropyl)cyclohexane
C. 1-(1-Methylethyl)-2-(2-methylpropyl)cyclohexane
D. 1-(1-Methylethyl)-2-butylclohexane

Explanation

To solve the problem of determining the correct IUPAC name for the hydrocarbon (R) described, we will follow these steps:

### Step 1: Identify the Structure of the Hydrocarbon
The hydrocarbon has a six-membered ring with no unsaturation, indicating it is a saturated cyclic compound. The simplest saturated six-membered ring is cyclohexane (C6H12).

### Step 2: Determine the Alkyl Groups
The problem states that there are two alkyl groups attached to the ring adjacent to each other:
- One alkyl group has 3 carbon atoms with branching at the first carbon.
- The other alkyl group has 4 carbon atoms, with the second carbon substituted.

### Step 3: Draw the Alkyl Groups
1. **Three-Carbon Alkyl Group (with branching at the first carbon)**: This can be represented as an isopropyl group (C3H7) where the branching occurs at the first carbon. The structure is:
```
CH3
|
CH3-CH
|
CH2
```

2. **Four-Carbon Alkyl Group (with substitution at the second carbon)**: This can be represented as a butyl group (C4H9) where the second carbon has a methyl substitution. The structure is:
```
CH3
|
CH2-CH-CH2
|
CH3
```

### Step 4: Positioning the Alkyl Groups on the Cyclohexane Ring
Since the two alkyl groups are adjacent, we can place them on the cyclohexane ring. We will assume the first carbon of the cyclohexane is where we start numbering.

### Step 5: Numbering the Ring
We will number the cyclohexane ring starting from one of the carbons where the alkyl groups are attached:
- Position 1: Isopropyl group
- Position 2: Butyl group

### Step 6: Naming the Compound
To name the compound, we follow the IUPAC naming conventions:
1. Identify the longest carbon chain in the substituents.
2. Assign numbers to the substituents based on their positions on the ring.
3. Combine the names of the substituents in alphabetical order.

The isopropyl group is at position 1, and the butyl group is at position 2. The correct name will be:
- 1-Isopropyl-2-butylcyclohexane

### Final Answer
The correct IUPAC name of compound (R) is **1-Isopropyl-2-butylcyclohexane**.

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