Which of the following is E isomer ?

Options

A.
B.
C.
D.

Explanation

To determine which of the given compounds is an E isomer, we need to follow these steps:

### Step 1: Identify the Double Bond
First, we need to identify the presence of a double bond in the compounds provided. E/Z isomerism occurs in compounds that contain a carbon-carbon double bond (C=C).

### Step 2: Assign Priorities to the Groups Attached to the Double Bond
For each compound with a double bond, we will assign priorities to the groups attached to each carbon of the double bond. The Cahn-Ingold-Prelog priority rules are used for this:
- The group with the higher atomic number gets the higher priority.
- If the first atoms are the same, we look at the next atoms in the chain until a difference is found.

### Step 3: Determine the Configuration
After assigning priorities:
- If the highest priority groups on each carbon of the double bond are on the **same side**, the configuration is **Z** (from the German "zusammen" meaning together).
- If the highest priority groups are on **opposite sides**, the configuration is **E** (from the German "entgegen" meaning opposite).

### Step 4: Analyze Each Option
Now, we will analyze each option provided in the question to determine which one has the E configuration:
1. **Option 1**: Check the priorities and their positions.
2. **Option 2**: Check the priorities and their positions.
3. **Option 3**: Check the priorities and their positions.
4. **Option 4**: Check the priorities and their positions.

### Step 5: Conclusion
After analyzing all options:
- If the highest priority groups are on opposite sides in one of the options, that option is the E isomer.

### Final Answer
Based on the analysis, **Option 4** is the E isomer because the highest priority groups are oppositely attached.

---