Why can the following protected carboxylic acid NOT be deprotected with acid hydrolysis conditions?

• A. Hydrolysis conditions will react with the benzene ring, too.
• B. Actually, this molecule can be deprotected with acid hydrolysis.
• C. Hydrolysis conditions will react with the amine, too.
• D. Hydrolysis conditions will react with the epoxide, too.

Answer: (D)

Verified step by step guidance

1. Identify the functional groups present in the molecule. The structure contains an amine group (NH2), an ester linkage (O=C-O), a benzene ring, and an epoxide group (a three-membered cyclic ether).
2. Understand the mechanism of acid hydrolysis. Acid hydrolysis typically involves the addition of water in the presence of an acid, which can cleave ester bonds to yield a carboxylic acid and an alcohol.
3. Consider the reactivity of the epoxide group under acidic conditions. Epoxides are highly strained and reactive, especially under acidic conditions, where they can undergo ring-opening reactions.
4. Analyze the potential side reactions. In the presence of acid, the epoxide group is likely to react before the ester group is hydrolyzed, leading to unwanted side reactions and preventing selective deprotection of the ester.
5. Conclude that the presence of the epoxide group makes it unsuitable for deprotection using acid hydrolysis, as the epoxide will react with the acid, complicating the reaction and preventing the desired outcome.