Ch. 3 - Alkanes and Cycloalkanes: Properties and Conformational Analysis

Mullins - Organic Chemistry: A Learner Centered Approach 1st Edition

Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Not the one you use?Change textbook

Mullins 1st Edition

Ch. 3 - Alkanes and Cycloalkanes: Properties and Conformational Analysis

Problem 57e

Chapter 2, Problem 57e

For each chair on the left, place the substituents on the flipped chair. [Recall that the axial/equatorial designation changes from one chair to the next, but the carbon to which the substituent is attached does not.]
(e)

Verified step by step guidance

Step 1: Understand the concept of chair flipping in cyclohexane. When a chair conformation flips, axial substituents become equatorial, and equatorial substituents become axial. However, the substituents remain attached to the same carbon atoms.

Step 2: Identify the substituents and their positions on the original chair conformation. In this case, there is a bromine (Br) substituent at carbon 3 in the axial position and another bromine (Br) substituent at carbon 4 in the equatorial position.

Step 3: Draw the flipped chair conformation. Ensure that the carbon numbering remains consistent (carbon 1 through carbon 6) and the overall structure of the cyclohexane ring is preserved.

Step 4: Place the substituents on the flipped chair conformation. For carbon 3, the bromine substituent that was axial in the original chair conformation will now be equatorial. For carbon 4, the bromine substituent that was equatorial in the original chair conformation will now be axial.

Step 5: Double-check the positions of the substituents to ensure accuracy. Verify that the axial/equatorial designations have been correctly swapped and that the substituents remain attached to their respective carbons.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Chair Conformation

Chair conformation is a three-dimensional representation of cyclohexane that minimizes steric strain. In this conformation, the carbon atoms are arranged in a way that allows for staggered bonds, making it the most stable form of cyclohexane. Understanding chair conformation is essential for visualizing how substituents are positioned in space.

Axial and Equatorial Positions

In chair conformations, substituents can occupy two types of positions: axial and equatorial. Axial substituents are oriented perpendicular to the plane of the ring, while equatorial substituents are oriented parallel to the plane. The designation of these positions changes when the chair conformation is flipped, which is crucial for predicting the stability of different substituent arrangements.

Flipping the Chair

Flipping the chair refers to the process of converting one chair conformation of cyclohexane into another. This involves rotating the ring structure, which causes axial substituents to become equatorial and vice versa. This concept is important for understanding how the spatial arrangement of substituents affects the overall stability and reactivity of cyclohexane derivatives.

Recommended video:

Guided course

05:12

The 3 important factors when drawing chairs

Related Practice

Textbook Question

What is the mistake that was made in drawing each of the flipped chairs on the right from the chair on the left? [In these, assume that the angle through which you view the chair conformations doesn't change.]

(a)

1123

views

Textbook Question

For each chair on the left, place the substituents on the flipped chair. [Recall that the axial/equatorial designation changes from one chair to the next, but the carbon to which the substituent is attached does not.]

(c)

646

views

Textbook Question

Using the numbers shown in the chair conformation on the left, label the carbons of the flipped chair on the right. [Assume that the angle through which you view the chair conformation doesn't change.]

1451

views

Textbook Question

For each pair of conformations shown, choose which is most stable. If both are equally stable, then write 'no difference.' [If both conformations have the same number of axial substituents, choose the one with the smallest axial substituents.]

(e)

(f)

Looking down the indicated bond, show the three most stable conformations and choose the one that is most stable. Be sure that the first Newman projection you show is the one you see initially (before rotation). [Why should none of your three Newman projections show eclipsed conformations?]

(e) <IMAGE>

982

views

For each chair on the left, place the substituents on the flipped chair. [Recall that the axial/equatorial designation changes from one chair to the next, but the carbon to which the substituent is attached does not.](e)

Verified video answer for a similar problem:

Key Concepts

Chair Conformation

Axial and Equatorial Positions

Flipping the Chair

For each chair on the left, place the substituents on the flipped chair. [Recall that the axial/equatorial designation changes from one chair to the next, but the carbon to which the substituent is attached does not.]
(e)