Which one the following is an Z isomer ?

Options

A.
B.
C.
D.

Answer

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

### Step 1: Understand the Definition of Z and E Isomers
- Z isomers (from the German "zusammen") have the higher priority groups on the same side of the double bond.
- E isomers (from the German "entgegen") have the higher priority groups on opposite sides of the double bond.

### Step 2: Identify the Compounds
- Let's assume we have four compounds to analyze. For each compound, we will identify the substituents attached to the double bond.

### Step 3: Assign Priorities
- For each compound, assign priorities to the substituents based on the Cahn-Ingold-Prelog priority rules. The priority is determined by the atomic number of the atoms directly attached to the double-bonded carbon atoms. Higher atomic numbers receive higher priority.

### Step 4: Analyze the Position of the Higher Priority Groups
- For each compound, check the position of the higher priority groups:
- If both higher priority groups are on the same side of the double bond, it is a Z isomer.
- If they are on opposite sides, it is an E isomer.

### Step 5: Compare with Given Options
- After analyzing all four compounds, identify which one has the higher priority groups on the same side. This compound will be the Z isomer.

### Conclusion
- The correct answer will be the compound that has the higher priority groups on the same side of the double bond.