# What are the E and Z isomers of cinnamic acid?

Mar 20, 2016

See below.

#### Explanation:

Cinnamic acid is 3-phenylpropenoic acid.

Each alkene carbon has two different groups, so the molecule can exist as $E / Z$ isomers.

($E$)-Cinnamic acid has the phenyl and $\text{COOH}$ groups on opposite sides of the double bond.

In ($Z$)-cinnamic acid, the phenyl and $\text{COOH}$ groups are on the same side of the double bond.