# How many gauche interactions does this chair conformer have?

## How many gauche interactions does this chair conformer have?

Conformer 1 is the most stable because there are only two (CH3-OH) gauche interactions present, whereas there are three gauche interactions present in conformers 2 and 3 (one CH3-CH3, one CH3-OH, and one OH-OH).

## What is gauche in a chair conformation?

Gauche. Description given to two substitutents attached to adjacent atoms when their bonds are at 60o with respect to each other. Syn. Description given to two substitutents attached to adjacent atoms when their bonds are at 0o with respect to each other. Conformations.

What makes a chair conformation more stable?

The chair conformation is more stable because it does not have any steric hindrance or steric repulsion between the hydrogen bonds. These are hydrogens in the axial form. These hydrogens are in an equitorial form.

How do you know if a chair conformation is stable?

To Determine Chair Conformation Stability, Add Up The A-Values For Each Axial Substituent. The Lower The Number, The More Stable It is.

### What is the most stable chair conformation?

The most stable conformation of methylcyclohexane is the chair conformation in which the methyl group is equatorial. The alternative chair conformation, in which the methyl group is axial, is 7.3 kJ/mol higher in energy.

### Why are axial groups unfavorable?

Because axial bonds are parallel to each other, substituents larger than hydrogen experience greater steric crowding when they are oriented axial rather than equatorial.

Is gauche eclipsed?

Gauche: The relationship between two atoms or groups whose dihedral angle is more than 0o (i.e., eclipsed) but less than 120o (i.e., the next eclipsed conformation). A conformation which has one or more gauche interactions is can be called a gauche conformation.

Is gauche staggered or eclipsed?

This particular staggered conformation is called anti. This is called the gauche conformation. The gauche form is less stable than the anti form due to steric hindrance between the two methyl groups but still is more stable than the eclipsed formations.

## Which is the most stable of the two chair conformers shown?

The most stable conformation of cyclohexane is the chair form shown to the right. The C-C-C bonds are very close to 109.5o, so it is almost free of angle strain. It is also a fully staggered conformation and so is free of torsional strain.

## Why does cyclohexane adopt a chair conformation?

Explanation: The carbons in cyclohexane are all sp3 hybridized. The ideal angle between atoms connected to anything that is sp3 hybridized is 109.5 degrees. In a chair conformation, the angles of all the atoms in the ring can adopt this positioning, and thus the molecule does not experience any ring or angle strain.

Why is chair conformation of cyclohexane more stable?

Answer: Chair conformation of cyclohexane is more stable than boat form because in chair conformaion the C-H bonds are equally axial and equatorial, i.e., out of twelve C-H bonds, six are axial and six are equatorial and each carbon has one axial and one equatorial C-H bond.

Which conformation is more stable chair or boat?

The chair conformation is the most stable conformation of cyclohexane. A second, much less stable conformer is the boat conformation. This too is almost free of angle strain, but in contrast has torsional strain associated with eclipsed bonds at the four of the C atoms that form the side of the boat.