How many carbon-carbon double bonds are present in the structure of ibuprofen?

• A. $0$
• B. $3$
• C. $1$
• D. $2$

Answer: (C)

Verified step by step guidance

1. Step 1: Recall the structure of ibuprofen, which is a nonsteroidal anti-inflammatory drug (NSAID). It contains a benzene ring (aromatic ring), a carboxylic acid group, and an isobutyl side chain attached to the benzene ring.
2. Step 2: Identify the types of carbon-carbon bonds present in ibuprofen. The benzene ring contains alternating double bonds, but these are aromatic bonds, not isolated carbon-carbon double bonds (alkenes).
3. Step 3: Examine the side chains and functional groups attached to the benzene ring. The isobutyl group and the carboxylic acid group do not contain any carbon-carbon double bonds.
4. Step 4: Understand that aromatic double bonds in benzene are delocalized and considered part of the aromatic system, not counted as typical carbon-carbon double bonds (alkenes).
5. Step 5: Conclude that ibuprofen contains exactly one carbon-carbon double bond, which is part of the aromatic benzene ring system, and no other isolated carbon-carbon double bonds are present.