Stereochemistry Module Goal

After completing this module, students should be able to represent and classify stereoisomeric relationships and evaluate the implications of synthesizing small molecules for use as chiral drugs.

Assumed Prior Knowledge

Students should know basic concepts from general chemistry as well as how to draw organic molecules in line-angle formula using wedges and dashes to represent tetrahedral carbon atoms.

Green & Sustainable Chemistry Concepts Covered

• Reaction efficiency: Minimizing the quantities of chemicals (reactants, reagents, solvents, etc.), energy and water used to make a chemical, material or product
• Efficiency metrics: Calculating the efficiency of reactions or processes, for example through process mass intensity, atom economy or other efficiency metrics
• Process efficiency: Reducing the number of synthetic/process steps to produce chemicals, materials and products
• Renewables: Utilizing renewable feedstocks in place of petroleum feedstocks
• Catalysis and recycling: Replacing stoichiometric reagents with catalysts or recycling reagents or solvents
• Lifecycle impacts of chemicals: Understanding how chemicals are produced and the social, environmental and economic impacts of their extraction or manufacture
• Chemicals in the environment: Understanding the fate, persistence and degradability of man-made chemicals in the environment
• Chemical hazards and exposure: Identifying environmental, safety and health hazards, as well as potential sources of exposure.  Selection and design of chemicals that are less hazardous alternatives to known chemicals and products

UN Sustainable Development Goals

This module connects to the UN SDGs of Good Health and Well-being, Gender Equality, Reduced Inequalities, and Responsible Production and Consumption.

Learning Objectives

Students will be able to:

1. Define chirality and identify stereocenters in organic compounds, including pharmaceutical drugs.
2. Draw the possible stereoisomers of various molecules.
3. Distinguish between enantiomers, diastereomers and meso compounds and explain their physical properties, especially in chiral environments such as the human body.
4. Use the Cahn-Ingold-Prelog convention to correctly assign R and S nomenclature.
5. Define racemic mixture and determine the enantiomeric excess of a mixture.
6. Explain some implications of stereoisomerism with respect to health and well being.
   

Special Resource: Toxicity Estimation Software Tool (TEST)

Students will need to download the TEST tool (Toxicity Estimation Software Tool) from the EPA’s website in order to use it for an in-class discussion and out-of-class homework assignment. It is free to download from the EPA website. Students will also need general access to the internet to do outside research.

Summary of Module Materials

Unit 1: Introduction to Chirality

1.1 Pre-class homework (20 minutes outside class). Problem on the similarities and differences between R- and S- carvone
1.2 Lecture (10 minutes in class). Slides with an introduction to the module goals, chirality, and embedded discussion question about the pre-class homework
1.3 Lecture (20 minutes in class). Slides that: identify chiral centers, give an introduction to the theme for the module (WHO Model List of Essential Medicines), and contain a think-pair-share question (identifying chiral centers in pharmaceuticals).
1.4 Lecture (20 minutes in class). Slides on the importance of chirality with historical examples and applications.
1.5 Unit 1 homework (20 minutes outside class). Problems on identifying chiral and achiral compounds and counting chiral centers in pharmaceuticals used to treat and prevent malaria

Unit 2: Enantiomers and the Cahn-Ingold-Prelog Rules

1.6 Lecture (15 minutes in class) Slides with a how-to guide on drawing enantiomers followed by an embedded practice question on drawing the pair of enantiomers for both ibuprofen and nicotine
1.7 Lecture (15 minutes in class) Slides with a how-to guide on using the CIP rules to designate chiral centers as R or S followed by an embedded practice question on labelling the chiral centers in ibuprofen and nicotine
1.8 Unit 2 homework (20 minutes outside class). Problem on drawing pairs of enantiomers of several pharmaceuticals and labeling their chiral centers using the CIP rules

Unit 3: Classification of Stereoisomers and their Physical Properties

1.9 Lecture (30 minutes in class) Slides with descriptions and examples of diastereomers and meso compounds including embedded practice problems on drawing and identifying them
1.10 Lecture (20 minutes in class) Slides covering optical activity and Fischer projections including embedded practice problem on drawing Fischer projections from line-angle structures
1.11 Unit 3 homework (30 minutes outside class). Problems on drawing the stereoisomers of mefloquine, an antimalarial drug from the Unit 1 homework

Unit 4: Implications of Chirality on Health and Well-being

1.12 Lecture (15 minutes in class) Slides with descriptions and examples of racemic mixtures
1.13 Lecture (35 minutes in class) Slides describing chiral resolution and chiral synthesis; discussion and activity on predicting toxicological effects of new compounds
1.14 Units 1-4 SOCME homework (90 minutes outside class). Comprehensive assignment linking all modules together. Students will use a specific antibiotic to answer all the questions. Outside research will be required as well as using TEST.

Option A: List downloads one-to-one like they are presented in the Module Overview doc:

Stereochemistry Module Teaching Materials

Zipped folders contain all learning material downloads. PowerPoint slide decks, several homework assignments, and a summative assessment are included in this module.  

Option B: List downloads as two links, with or without the content listed:

Stereochemistry Module Teaching Materials

Zipped folders contain all learning material downloads. PowerPoint slide decks, several homework assignments, and a summative assessment are included in this module.  

Download all Student Materials
[Zipped Folder]

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Materials Included:

• Summative Assessment- Instructor Edition
• Summative Assessment- Student Edition
• Pre-Unit 1 Homework- Instructor Edition
• Pre-Unit 1 Homework- Student Edition
  
• Unit 1 PowerPoint
  
• Unit 1 Homework- Instructor Edition
  
• Unit 1 Homework- Student Edition
  
• Unit 2 PowerPoint
  
• Unit 2 Homework- Instructor Edition
  
• Unit 2 Homework- Student Edition
  
• Unit 3 PowerPoint
  
• Unit 3 Homework- Instructor Edition
  
• Unit 3 Homework- Student Edition
  
• Unit 4 PowerPoint
  
• Units 1-4 SOCME- Instructor Edition
• Units 1-4 SOCME- Student Edition