Enantiomeric Excess Percent Optical Purity Calculations and Logic

Enantiomeric Excess Percent Optical Purity in Series by Leah4sci

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 […]

Polarimetry in Optical Activity

Polarimetry Optical Activity in Chirality and Stereochemistry by Leah4sci

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 […]

Swap Method for finding R and S Configurations Chirality

swap method for r and s stereochemistry

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 […]

Stereochemistry of Amino Acids RS to DL

Amino Acid Stereochemistry RS 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 […]

Finding R and S When Group 4 is Forward

Finding R and S when Group number 4 is forward by Leah4sci

Chirality/Stereochemistry Video Series: Video 3 This video shows you why and how to reverse R and S when group #4 is forward to help you quickly and easily master relative configurations when studying chirality and stereochemistry. (Watch on YouTube: Group 4. Click cc on bottom right for video transcription.) <– Watch Previous Video: R and […]

Fischer Projection R and S Stereochemistry Trick

Fischer Projection Stereochemistry Finding R and S configurations

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 […]

R and S configuration for Lengthy Complex Substituents

R and S configurations for complex chiral molecules

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 […]

Newman Projection Stereochemistry R & S Trick

Newman projection stereochemistry r and s configuratios tutorial video

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: […]

Chirality and Stereochemistry Practice Quiz

Chirality and Stereochemistry R S Enantiomers Diastereomers Meso Tutorial Series

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 […]

R and S Configuration using Cahn Ingold Prelog Priority Rules

R and S Configuration Cahn Ingold Prelog rules for ranking by Leah Fisch

Chirality/Stereochemistry Video Series: Video 2 Chiral carbons are identified as having 4 unique substituents. Finding the Absolute Configuration – R and S comes as a result of ranking and order substituents, specifically by noting the configuration of the top 3 groups. This video shows you how to prioritize substituents to find R and S configurations […]