Question

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

Answer 1

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

Explanation:

For the molecule to exhibit `E,Z` isomerism, the `"C=C"` bond must be between `"C-2"` and `"C-3"`.

Then the only prochiral carbon is `"C-4"`.

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

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