# How can I draw the molecular formula for an unsaturated alkyl chloride C_5H_9Cl for optical activity or E,Z isomerism?

Jul 26, 2015

The only possible compound is 4-chloropent-2-ene.

#### Explanation:

For the molecule to exhibit $E , Z$ isomerism, the $\text{C=C}$ bond must be between $\text{C-2}$ and $\text{C-3}$.

Then the only prochiral carbon is $\text{C-4}$.

The compound must be 4-chloropent-2-ene.

The structure above shows ($2 E , 4 S$)- 4-chloropent-2-ene.