Chirality is a tough organic chemistry topic. But if you’re reading this, you already know that. Be sure to watch my Chirality and Stereochemistry video series to make sense of chiral atoms, enantiomers, absolute configuration and finding R/S for simple and complex molecules. The cheat sheet below is meant to serve as a study guide […]
Stereochemistry of Amino Acids RS to DL
Amino acids are biologically active molecules. 19 of the 20 common amino acids have a chiral alpha carbon. 2 amino acids (Leucine and Threonine) have a second chiral center in their side chain. This video shows you how to: Find R/S for 3-D amino acids Find R/S and D/L for amino acid Fischer projections Trick […]
R and S configuration for Lengthy Complex Substituents
Chirality/Stereochemistry Video Series: Video 5 R and S configurations are found by ranking substituents on a chiral carbon. This is relatively straight-forward when substituents contain 1-3 atoms. This gets more confusing when the substituents are long, complex, and contain many of the same atoms. This orgo tutorial video shows you how to approach lengthy and […]
Chirality and Stereochemistry Practice Quiz
The key to mastering chirality and stereochemistry is through practice, practice, and more practice. But where do you get all those practice problems? After reviewing the videos in my Chirality and Stereochemistry series, and working through the simple questions in each, see how well you’ve mastered the material by trying my Stereochemistry Practice Quiz below. The […]
Enantiomeric Excess Percent Optical Purity Calculations and Logic
Enantiomeric excess percentage (aka optical purity percentage) calculations are one of the few equations you’ll come across in your orgo course. This video gives you a step by step breakdown and practice examples. You’ll see how to find the percent excess via logic and see the numbers side by side. (Watch on YouTube: Optics 3. Click […]
Specific Rotation Calculation in Optical Activity
Specific Rotation calculations are a useful tool in optical activity. This video will help you understand the factors influencing specific rotation such as observed rotation, g/mL, path-length, wavelength, and temperature. You will see a detailed breakdown of the equation along with a few examples to follow along. (Watch on YouTube: Optics 2. Click CC for video transcription.) <– […]
Polarimetry in Optical Activity
Polarimetry is the key to understanding chiral molecules in terms of optical activity. This video goes behind the scenes of the polarimeter to help you understand what plane polarized light has to do with chiral molecules. Part 1 (of 3) in this mini series explains + D and – L, dextrorotatory and levorotatory, and their (lack […]
Newman Projection Stereochemistry R & S Trick
Chirality/Stereochemistry Video Series: Video 7 Finding R and S configurations for non-traditional molecules can be somewhat tricky. This video teaches you how to quickly find configurations of molecules presented in a Newman Projection. Learn how to view the molecule and quickly assign priority WITHOUT the need to redraw into a sawhorse projection. (Watch on YouTube: […]
Fischer Projection R and S Stereochemistry Trick
Chirality/Stereochemistry Video Series: Video 6 Fischer projections provide a simple 2-dimensional representation for complex 3-dimensional structures. Which is great for drawing complex molecules, but not so much fun if asked to determine R and S configurations. Many books and professors will have you redraw the Fischer projection into a 3-dimensional sawhorse or skeletal structure. I […]
Swap Method for finding R and S Configurations Chirality
Chirality/Stereochemistry Video Series: Video 4 R and S configurations are pretty straight-forward when priority group #4 is conveniently in the back of the molecule. There’s even a quick trick for when group #4 is forward (as taught in this video). But what happens when priority group #4 is in the plain of the page? Do […]
