Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

4. Alkanes and Cycloalkanes

Equatorial Preference

Organic Chemistry

4. Alkanes and Cycloalkanes

Equatorial Preference

Previous problemNext problem

8:31 minutes

Problem 74f

Textbook Question

Draw the two chair conformers for each of the following and indicate which conformer is more stable:
f. cis-1-ethyl-4-isopropylcyclohexane

Verified step by step guidance

Step 1: Understand the structure of cis-1-ethyl-4-isopropylcyclohexane. The 'cis' designation means that both substituents (ethyl and isopropyl groups) are on the same side of the cyclohexane ring. This will be important when placing the groups in the chair conformations.

Step 2: Draw the basic chair conformation of cyclohexane. Label the carbon atoms in the ring to help with substituent placement. For example, assign carbon-1 to the position where the ethyl group is attached and carbon-4 to the position where the isopropyl group is attached.

Step 3: Place the substituents on the chair conformation. Since the substituents are 'cis,' both groups must either be in axial positions or both in equatorial positions. Draw one conformer with both substituents in axial positions and another conformer with both substituents in equatorial positions.

Step 4: Evaluate the stability of each conformer. Recall that larger groups prefer the equatorial position due to reduced steric hindrance. Compare the steric interactions in the axial positions versus the equatorial positions for both the ethyl and isopropyl groups.

Step 5: Conclude which conformer is more stable. The conformer with both substituents in equatorial positions will generally be more stable because it minimizes steric hindrance between the bulky groups and the axial hydrogens on the ring.

Verified video answer for a similar problem:

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

Video duration:

Play a video:

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 and torsional strain. In this conformation, the carbon atoms are arranged in a staggered manner, allowing for more stable interactions between substituents. Understanding chair conformations is crucial for analyzing the stability of cyclohexane derivatives, as different substituents can occupy axial or equatorial positions, affecting overall stability.

Cis and Trans Isomerism

Cis and trans isomerism refers to the spatial arrangement of substituents around a ring or double bond. In the context of cyclohexane, 'cis' indicates that substituents are on the same side of the ring, while 'trans' means they are on opposite sides. This arrangement significantly influences the steric interactions between substituents, which in turn affects the stability of the conformers, making it essential to identify the correct isomer when analyzing stability.

Steric Hindrance

Steric hindrance is the repulsion between atoms that occurs when they are brought close together, often due to the size of substituents. In cyclohexane derivatives, larger groups prefer equatorial positions to minimize steric interactions with other substituents. Recognizing which conformer has less steric hindrance is key to determining which chair conformation is more stable, as lower steric strain typically correlates with greater stability.

Watch next

Master Equatorial Preference with a bite sized video explanation from Johnny

Start learning

Related Videos

Related Practice

Textbook Question

a. Draw both chair conformations of cis-1,4-dimethylcyclohexane, and determine which conformer is more stable.

b. Repeat for the trans isomer.

c. Predict which isomer (cis or trans) is more stable.

Textbook Question

Draw the two chair conformations of each compound, and label the substituents as axial and equatorial. In each case, determine which conformation is more stable.

e. cis-1-ethyl-4-methylcyclohexane

f. trans-1-ethyl-4-methylcyclohexane

Textbook Question

Draw the two chair conformations of each compound, and label the substituents as axial and equatorial. In each case, determine which conformation is more stable.

a. cis-1-ethyl-2-isopropylcyclohexane

b. trans-1-ethyl-2-isopropylcyclohexane

Textbook Question

Draw the two chair conformations of each of the following substituted cyclohexanes. In each case, label the more stable conformation.]

c. cis-1-ethyl-4-isopropylcyclohexane

d. trans-1-ethyl-4-methylcyclohexane

Textbook Question

Draw the two chair conformers for each of the following and indicate which conformer is more stable:

c. trans-1-ethyl-2-isopropylcyclohexane

Textbook Question

Bromine is a larger atom than chlorine, but the equilibrium constants in Table 3.9 indicate that a chloro substituent has a greater preference for the equatorial position than does a bromo substituent. Suggest an explanation for this fact.

Textbook Question

Draw the most stable conformer of the following molecule. (A solid wedge points out of the plane of the paper toward the viewer. A hatched wedge points back from the plane of the paper away from the viewer.)

Textbook Question

Which has a higher percentage of the diequatorial-substituted conformer compared with the diaxialsubstituted conformer: trans-1,4-dimethylcyclohexane or cis-1-tert-butyl-3-methylcyclohexane?

Show more practices

Download the Mobile app

Privacy

Do not sell my personal information

Accessibility

Patent notice

Sitemap

Draw the two chair conformers for each of the following and indicate which conformer is more stable: f. cis-1-ethyl-4-isopropylcyclohexane

Key Concepts

Chair Conformation

Cis and Trans Isomerism

Steric Hindrance

Watch next

Draw the two chair conformers for each of the following and indicate which conformer is more stable:
f. cis-1-ethyl-4-isopropylcyclohexane