Strain difference

[Kevin Chang 2I]

In a conformation, how can one distinguish torsional strain from steric strain?

[Kiara Quinn 3B]

Torsional Strain is a force that opposes rotation of a part of a molecule about a bond whereas steric strain occurs when there is a non bonded interaction that is too close together. For example, in the boat conformation, there would be a lot of steric strain due to the flagpole interactions. Torsional strain is often caused by the eclipsed hydrogens (pg 108 of the course reader). Hope this helps!