Stereochemistry--Mental Gymnastics

With our first reaction and mechanism in the books, we now usher in a topic of Organic Chemistry called Stereochemistry. This series kicks off with a brief overview of isomerism (structural, geometric, and most importantly stereo) and then shifts completely to stereochemistry. We'll discuss, what stereochemistry is, how to identify a stereocenter, how to assign R or S configuration to a stereocenter, how to determine relationships between molecules based on their stereochemistry, and more. Stereochemistry is one of those things that will ALWAYS come back in both semesters of Organic Chemistry, so make sure to be comfortable with the concepts before charging onward.

Study Guide(s):

Worksheet(s) & Solution(s):

Videos:

  1. Intro to Stereochemistry and Isomerism

    https://joechem.io/videos/17 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we start off by talking about the different types of isomerism: structural, geometric, and stereo. This serves as a nice segue into Stereochemistry, a key concept in Organic Chemistry.

  2. Assigning R & S--Conventionally and with the Double Switch

    https://joechem.io/videos/18 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we introduce the concept of evaluating whether a stereocenter (aka an atom that is attached to four different "groups") has an R or an S configuration. We talk about how to go about labeling a stereocenter as R or S when the lowest priority group is away from you or directly toward you (the two "easier" scenarios). We also talk about the "Double Switch" (a nice organic life hack) for when the lowest priority group of a stereocenter is neither facing away from you nor toward you.

  3. Stereochemical Relationships and Meso Structures

    https://joechem.io/videos/19 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we look at the various relationship types of stereoisomerism two structures can have with one another: enantiomers (mirror images of each other) and diastereomers (not mirror images of each other, but still stereoisomers). We then also talk about what it means to be meso, why meso structures are achiral, and how to identify meso structures.

  4. How to Handle Fischer Projections

    https://joechem.io/videos/20 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we talk about another way structures can be drawn on flat paper: Fischer Projections. Some teachers will wait to talk about these suckers until Carbohydrates, but we take a look at them here, talk about their conventions, and assign R&S to them.

  5. Chiral Structures and Optical Activity--Putting It All Together

    https://joechem.io/videos/105 for video on jOeCHEM and attached worksheet + solution (below video on jOeCHEM aka the link). In this video, we look at an overview of chirality and stereochemistry and put everything all together from what we covered in the world of stereochemistry: stereoisomerism + molecule pair relationships (enantiomers, diastereomers, etc), assigning R & S, being meso, etc.