The atoms that would sterically interact with methyl group located axially are highlighted in pink color in the attached image.
Further Explanation:
The stereoisomer of a molecule that has same chemical formula and connectivity of bond but differs in the arrangement of the atoms in space is known as conformer. The rotation about the carbon-carbon single bond can lead to the formation of conformer of a molecule.
There are four conformers of cyclohexane molecule as follows:
- Chair conformation
- Boat conformation
- Twist boat conformation
- Half chair conformation
Chair conformation is considered as the best conformation of cyclohexane. The hydrogen in blue denote the axial positions and the hydrogen in pink denote equatorial positions. (Refer to the attached image)
The stable conformation is that in which the bulky groups such as hydroxyl, methyl, and nitro group occupy the equatorial positions while the relatively small groups such as hydrogen atoms occupy axial positions. The reason is that the axially placed substituents suffer more steric repulsion and that generates strain in the molecule. The strain leads to high energy and thus less stability.
While writing the chair conformation the bulkier groups are preferentially placed at equatorial positions. The conformation that has bulky group at equatorial position is more favorable than the conformation that has bulky group at axial position. The reason for the stability of the conformation is diaxial interactions.
1,3-diaxial interaction: The 1,3-diaxial interactions occur among the axial substituent present at 1 and 3 positions.
The conformation in the problem has axial substituent hydrogen and bromine at the two positions 3 and 3’ which lead to 1,3-diaxial strain in the molecule and makes it unstable. (Refer to the attached image)
Learn more:
1. Balanced chemical equation brainly.com/question/1405182
2. Oxidation and reduction reaction: brainly.com/question/2973661
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Conformation of cyclohexane
Keywords: Cyclohexane, planar, chair conformation, axial positions, equatorial positions, steric repulsion, high energy, 1, 3-diaxial interaction, 1, 3-diaxial strain.