Question

Question #762dd

Answer 1

That particular chair conformation that is flipped, as opposed to the other chair conformations (which are generally more stable with six-membered rings), has all of its substituents in equatorial positions about the ring.

Equatorial positions are preferred over axial positions, because when substituents are in axial positions, it causes steric hindrance with the understood hydrogens in those positions, sometimes this is called diaxial interaction.

`"E"` is a reasonable answer, seemingly. All of the substituents are in equatorial positions, but the pattern is not representative of their orientation in space. For instance the alcohol adjacent to the ether group is "up" out of of the plane, and in the chair conformation you're considering it's pointing "down". Consider

where `"A"` denotes an axial substituent.

The best way to think about this is to literally imagine each of those substituents pointing up or down, and matching them to the cyclohexane in question.