Quick Menu

Cyclopentane

Cyclopentane

In cyclopentane since the angles are about 108o there is no significant destabilization due to angle strain.  There are three extremes in the conformations of cyclopentane.

Planar - The planar conformation has significant angle strain since all 5 hydrogens above and below the ring would be eclipsed.  This would be the least stable conformation

Envelope - More stable than planar cyclopentane and about the same stability as the half-chair conformation.  Notice that four of the carbons are coplanar resulting in significant torsional strain between eclipsed hydrogens.

Half-chair - More stable than the planar geometry since some of the torsional strain is relieved.  In this conformation three carbons are coplanar, while two are out of the plane.