Question

butylated hydroxytoluene (BHT) is a common preservative added to cereals and other dry foods. Its systematic name is 1 -hydroxy-2,6-di-tert- butyl-4-methylbenzene (tert-butyl is the common name for 1,1 -dimethylethyl). Draw the structure of BHT.

Short answer

BHT has a benzene ring with -OH at position 1, -CH3 at position 4, and -C(CH3)3 at positions 2 and 6.

Step-by-step solution

- Identify the Benzene Ring

Start by drawing a benzene ring, which is a hexagon with alternating double bonds inside.

- Add the Hydroxy Group at Position 1

At position 1 of the benzene ring, add an -OH group (also known as a hydroxy group).

- Add the Methyl Group at Position 4

At position 4 of the benzene ring, add a -CH3 group (also known as a methyl group).

- Add the tert-Butyl Groups at Positions 2 and 6

At positions 2 and 6 of the benzene ring, add -C(CH3)3 groups (these are the tert-butyl groups).

Key concepts

Systematic Nomenclature

Systematic nomenclature is a method of naming chemical compounds in a standardized way. It helps chemists communicate clearly and precisely about specific molecules. The International Union of Pure and Applied Chemistry (IUPAC) sets the rules for naming compounds.

The systematic name for BHT is 1-hydroxy-2,6-di-tert-butyl-4-methylbenzene. This name offers a lot of information:

• '1-hydroxy' means there is an -OH group attached at the first carbon atom of the benzene ring.
• '2,6-di-tert-butyl' indicates that there are tert-butyl groups attached to the second and sixth carbon atoms.
• '4-methyl' reveals a methyl group attached at the fourth position.

By following these rules, one can easily decipher the structure of BHT, or any other systematically named compound.

Benzene Ring

A benzene ring is a fundamental structure in organic chemistry. It is a six-membered carbon ring with alternating double bonds, often represented as a hexagon. Benzene rings are characterized by their stability due to resonance, where electrons are delocalized across all six carbon atoms.

In BHT:

• The base structure is a benzene ring.
• The presence of alternating double bonds is key to its stability.

Understanding the benzene ring is crucial because it serves as a backbone in many organic compounds.

Functional Groups

Functional groups are specific groups of atoms within molecules that determine the characteristics and chemical reactivity of those molecules. Common functional groups include hydroxyl (-OH), methyl (-CH3), and tert-butyl (-(CH3)3).

In BHT:

• A hydroxyl group (-OH) is attached to the first position of the benzene ring.
• Methyl groups (-CH3) are attached at the fourth position.
• Tert-butyl groups (-(CH3)3) are attached at the second and sixth positions.

Identifying these functional groups helps to predict how the molecule will behave in chemical reactions and interactions.