Conformations (Chairs, Newman, Fischer)

This section focuses on conformations—the different shapes a molecule can adopt as it rotates around single bonds. Even though the connectivity doesn’t change, these subtle shifts in 3D space can have a real impact on stability and reactivity. Some conformations minimize electron repulsion and steric crowding, while others force groups too close together, making them less favorable. Learning to recognize and evaluate these differences gives you a much clearer picture of how molecules actually behave, rather than just how they look on paper.

Newman projections give you a direct way to analyze these rotations by looking straight down a bond. This perspective makes it easy to compare arrangements like staggered and eclipsed conformations and to see how different groups interact with each other in space. It’s one of the most useful tools for understanding torsional strain and for quickly identifying the most stable arrangement around a single bond.

Chair conformations are how we represent cyclohexane rings in their most stable forms. Unlike flat drawings, these structures reflect the true three-dimensional shape of the molecule, where substituents can occupy axial or equatorial positions. That distinction turns out to be critical, because bulky groups strongly prefer one position over the other. Being able to draw, interpret, and compare chair conformations allows you to predict which version of a molecule is more stable and therefore more relevant.

Fischer projections offer a compact way to represent three-dimensional molecules, especially those with multiple stereocenters, on a flat page. While they look simple, they follow strict conventions that determine how bonds project in space. Once you’re comfortable with those rules, Fischer projections become a powerful shorthand for organizing and comparing stereochemical relationships without constantly redrawing full 3D structures.

Each of these representations is just a different lens for looking at the same underlying idea: molecules are not static. The tutorials that follow will walk you through how to draw each type correctly and how to use them to evaluate stability with confidence.