MCAT EXPERTISE
Determine which option you prefer for Fischer projection (R)/(S) designation and stick with
it. It’s more efficient to have a consistent method than to use all three interchangeably.
MCAT Concept Check 2.3:
Before you move on, assess your understanding of the material with these questions.
What is the difference between an (E) isomer and a (Z) isomer?(E): (Z):
How is priority assigned under the Cahn–Ingold–Prelog priority rules?For each of the Fischer projection manipulations listed below, is stereochemistry retained
or inverted?Switching a pair of substituents:
Switching two pairs of substituents:
Rotating the molecule 90°:
Rotating the molecule 180°: