Question

The requirement for anti-periplanar E2 reaction is that it can only occur in a chair conformation in which the leaving group (LG) occupies an ______ position.

Answer 1

The anti-periplanar E2 reaction requires the leaving group (LG) to occupy the equatorial position in a chair conformation.

Step-by-step explanation:

The requirement for anti-periplanar E2 reaction is that it can only occur in a chair conformation in which the leaving group (LG) occupies an equatorial position.

In a chair conformation, the bulky group is more stable when it is in the equatorial position, rather than the axial position. This is because the axial position experiences steric repulsion due to the proximity of other axial hydrogen atoms. By occupying the equatorial position, the bulky group experiences less repulsive interactions, making the chair conformation with the leaving group in the equatorial position more favored for the anti-periplanar E2 reaction.