Question

1. a. for cyclohexane, explain how chair conformations and axial/equatorial positions relate to steric strain. b. draw the chair conformation of the cyclohexane derivative shown.

Explanation:

Step1: Define chair - conformation and positions

Cyclohexane's chair - conformation has two types of hydrogen positions: axial and equatorial. Axial bonds are perpendicular to the ring plane, and equatorial bonds are in the approximate plane of the ring.

Step2: Explain steric strain relation

Steric strain occurs when atoms or groups are too close in space. In cyclohexane's chair - conformation, axial substituents can experience 1,3 - diaxial interactions, which are a form of steric strain. For example, two axial substituents on the 1 and 3 positions of the ring will repel each other due to their close proximity. Equatorial substituents are more stable as they have less steric hindrance.

For part b, as this is a text - based response and drawing is difficult, the general procedure for drawing the chair - conformation of a cyclohexane derivative is to first draw the chair - shaped hexagon. Then, assign the substituents to axial or equatorial positions based on their relative positions in the given flat - structure. Usually, substituents that are "up" in the flat - structure can be assigned to either an up - axial or up - equatorial position in the chair - conformation, and vice - versa for "down" substituents.

Answer:

a. In cyclohexane's chair - conformation, axial substituents can cause 1,3 - diaxial interactions leading to steric strain, while equatorial substituents have less steric hindrance.
b. Cannot be drawn in text, but the procedure is to draw the chair - shaped hexagon and assign substituents to axial/equatorial positions based on their relative up/down positions in the flat - structure.