Question

Potassium sorbate is added as a preservative to certain foods to prevent bacteria and molds from causing food spoilage and to extend the foods' shelf life. The IUPAC name of potassium sorbate is potassium \((2 E, 4 E)-2,4\)-hexadienoate. Draw a structural formula for potassium sorbate.

Short answer

Question: Draw the structural formula for potassium sorbate. Answer: The structural formula for potassium sorbate is CH2=CH-CH=CH-CH2-COO(-)K(+).

Step-by-step solution

Identify the parent chain

The parent chain consists of 6 carbon atoms, as indicated by the prefix "hexa" in the name. Since it's hexadienoate, there are two double bonds in the chain. Therefore, the parent chain can be represented as CH2=CH-CH=CH-CH2-COO-.

Identify the stereochemistry

The IUPAC name potassium \((2 E, 4 E)-2,4\)-hexadienoate indicates the stereochemistry of the double bonds. Both double bonds have the E configuration (trans).

Draw the hexadienoate anion

With the E configuration for both double bonds, the hexadienoate anion can be drawn as below: CH2=CH-CH=CH-CH2-COO- Now, we have a representation of the hexadienoate anion.

Add potassium counterion

Finally, we need to add the potassium counterion. As potassium sorbate is a salt, it's important to show the ionic bond between potassium and the hexadienoate anion. Replace the hydrogen in the carboxylic acid group with a potassium ion (K+). CH2=CH-CH=CH-CH2-COO(-) + K(+)

Finalize the structural formula

Combining all the components yields the structural formula of potassium sorbate: CH2=CH-CH=CH-CH2-COO(-)K(+)