SolutionsAnhydrides
1. Which anhydride?
Which acid gives, by dehydration, each anhydride: a) acetic anhydride; b) succinic anhydride; c) phthalic anhydride?
- Acetic acid (two molecules).
- Succinic (butanedioic) acid, intramolecularly.
- Phthalic (1,2-benzenedicarboxylic) acid, intramolecularly.
2. Aspirin
Aspirin is made by treating salicylic acid with acetic anhydride. Which group is acetylated, and what by-product forms?
The phenolic OH is acetylated, giving the ester acetylsalicylic acid; the by-product is acetic acid.