4.1 Build a model of cyclopentane, C5H10. Cyclopentane is a more flexible ring system than cyclobutane or
cyclopropane. A model of cyclopentane in a conformation with all the ring carbon atoms coplanar exhibits minimal deviation of the C-C-C bond angles from the normal tetrahedral bond angle.
a) How many eclipsing interactions are there in this planar conformation?
b) If one of the ring carbon atoms is pushed slightly above (or below) the plane of the other carbon atoms a model of the envelope conformation is obtained. Does the envelope conformation relieve some of the eclipsing interactions?