Organic Chemistry Lecture Notes: Writing Organic Reactions

Introduction

• Focus on basics of writing organic reactions.
• Builds on prior knowledge of acid and base chemistry.

General Reaction Process

• Start with a starting material.
• Use one or more steps to transform to a product.
• Reagents: Placed above the reaction arrow.
• Solvents: Placed below the arrow.
  • Solvents are generally non-reactive and facilitate the reaction.

Multi-step Reactions

• Reactions can involve multiple steps.
• Workup: Occurs after each step.
  • Involves a mild acidic solution to stop reaction progression.
  • Protonates negative species and quenches the reaction.

Example Reaction: Cyclohexanone to Ester

• Starting Material: Cyclohexanone.
• Target Product: Molecule with an ester functional group.
• Key Reagents and Solvent:
  • Grignard reagent (carbon-magnesium bond).
  • THF (solvent).
  • Acid chloride: Used in the reaction to form intermediate products.
• Mechanism:
  1. Grignard reaction with cyclohexanone.
     • Carbon (nonmetal) and magnesium (metal) form ionic bond.
     • Negative charge on carbon attacks carbonyl carbon.
  2. Workup results in alcohol formation from ketone.
  3. Acid chloride addition forms an intermediate.
  4. Workup removes protons and stabilizes product.

Types of Organic Reactions

• Substitution Reactions:
  • Nucleophile replaces a group on a carbon atom.
• Elimination Reactions:
  • Base removes a group, forming a double bond.
• Addition Reactions:
  • Addition of atoms across a double bond.
  • Important in reactions involving alkenes.

Conclusion

• Overview of chemical reaction processes.
• Single and multi-step reactions explained.
• Solvents play crucial role without participating in the reaction.
• Mention of reactions getting more complex.

Note

• Code for the video: Functional group ether.
• Encouragement for students to attend lectures.