Lecture Notes: Functional Groups in Organic Chemistry

Introduction

• Focus on learning six functional groups containing oxygen.
• Previous knowledge includes naming alkane functional groups and recognizing hydrocarbons like chloro, fluoro, bromo.

Alcohol

• General Formula: R-OH
  • R = any length of carbon chain (e.g., 1 carbon, 15 carbons, etc.).
• Identification:
  • Ends in "-ol" (e.g., methanol, ethanol).
  • OH group bonded to a carbon.
• Note: You only need to identify, not draw or name.

Ether

• General Formula: R-O-R
  • R's can be the same or different carbon chains.
• Identification:
  • Oxygen bonded between two carbon chains (e.g., dimethyl ether, diethyl ether).
  • Name includes "ether".

Aldehyde

• General Formula: Contains a carbon double-bonded to oxygen and single-bonded to hydrogen (end carbon).
• Identification:
  • Double-bonded oxygen on the last carbon.
  • Name ends in "-al" (e.g., formaldehyde).
• Example: Formaldehyde is the simplest aldehyde (one carbon).

Ketone

• General Formula: Similar to aldehyde but with double-bonded oxygen on a middle carbon.
• Identification:
  • Double-bonded oxygen on a middle carbon.
  • Name ends in "-one" (e.g., propanone, acetone).
• Example: Acetone, commonly used in nail polish remover and paint thinners.

Carboxylic Acid

• General Formula: Double-bonded O and OH group on the last carbon.
• Identification:
  • Double-bonded oxygen and OH together.
  • Name ends in "-oic acid" (e.g., propanoic acid, ethanoic acid).

Ester

• General Formula: Double-bonded oxygen to a single-bonded oxygen, then bonded to a carbon chain.
• Identification:
  • O-C linkage not to hydrogen but to another carbon chain.
  • Name ends in "-ate" (e.g., ethyl propanoate).
• Reaction Note: Esters are formed from reactions between carboxylic acids and alcohols, producing an ester and water.

Summary

• Focus on identifying functional groups by name suffix and structure.
• Understand the basic structure of each functional group based on examples provided.
• Recognize the importance of double-bonded oxygen in determining the type of functional group.

Important Suffixes

• Alcohol: -ol
• Ether: ether
• Aldehyde: -al
• Ketone: -one
• Carboxylic Acid: -oic acid
• Ester: -ate