Lecture Notes: Acid Hydrolysis of Esters

Introduction

• Topic: Acid Hydrolysis of Esters
• Key Concept: Splitting an ester into two components using water and an acid catalyst.
• Definition of Hydrolysis:
  • Hydro: Water
  • Lysis: Splitting
• Reverse Process: Opposite of esterification.

Process Overview

• Starting Materials:
  • An ester
  • Water (H2O)
• End Products:
  • Alcohol
  • Carboxylic Acid
• Catalyst: Acid (indicated by H⁺)

Step-by-Step Process

1. Identify the Ester and Water:
   • Begin with the chemical structure of the ester.
   • Add water to the reaction.
2. Splitting the Ester:
   • Split the ester into two halves.
   • One half becomes the carboxylic acid; the other half becomes the alcohol.
3. Rearranging Atoms:
   • OH from water attaches to the carboxylic acid half.
   • H from water attaches to the alcohol half.
4. Bond Orientation:
   • Pay attention to the C=O bond in ester.
   • Split at the C-O single bond.

Practice Problems

• Problem 1:
  • Step 1: Draw a line through the C-O single bond.
  • Step 2: Rewrite the carbon side and add an O to form carboxylic acid.
  • Step 3: Write the alcohol side starting with the oxygen.
• Example:
  • Ester is split to form a carboxylic acid and an alcohol.

Additional Examples

• Problem 2:
  • Ester drawn upside down; process remains the same.
  • Includes a substituent which remains unchanged through the process.

Important Points

• O from water goes to the carboxylic acid.
• H from water goes to the alcohol.
• Orientation: Orientation can be flipped for convenience, but process remains unchanged.

Conclusion

• Acid Hydrolysis: A method to "undo" esterification by splitting esters into alcohol and carboxylic acid using water and an acid catalyst.