Question

rank the following newman projections in order of decreasing energy, from least stable to most stable.

Explanation:

Step1: Identify steric hindrance

Steric interactions increase energy. The more bulky - group repulsions, the higher the energy and the less stable the conformation.

Step2: Analyze A

In A, there are multiple gauche - butane interactions between the large isopropyl groups, creating significant steric hindrance, so it has high energy.

Step3: Analyze B

B has fewer and less severe steric interactions compared to A. There are still some interactions between the isopropyl groups, but not as many as in A.

Step4: Analyze C

C has relatively less steric hindrance as the groups are more spread out compared to A and B, reducing the repulsions between the bulky groups.

Step5: Analyze D

D has the least steric interactions as the groups are arranged in a way that minimizes repulsions, so it is the most stable with the lowest energy.

Answer:

A > B > C > D