Draw and name the six isomeric cyclopentanes of molecular formula C 7 H 14 . These will include four constitutional isomers, of which two show geometric ( cis - trans ) stereoisomerism.

Hey everyone. Let's solve this problem and says draw and name all the ice americ cyclo butane is consistent with the formula C six H 12. Show geometric cIS trans where possible. Alright, so this question is asking for all the possible customers that are cyclo butane zones with the formula C six H 12. So cyclo butane means a ring of four carbons, Right? And the formula has to have C six H 12, which means there are two more carbons that are not on the parent chain or the parent ring. Right? So, the possibilities that we could have would be if we're numbering the ring like this, We could have two methyl groups on Carbons, one and 2. And just imagine all of these rings are numbered that way we can have carbons on one and three. And if I added, say any other like one in four, that would be the same as one and two. Right, Because it's just a four member ID ring Or I could have an ethyl group, right? 1, 2 carbons. So there's two carbons but they're coming off of the same carbon as an ethyl group. Okay, so these are the three possibilities. But it says to show geometric summers where possible there are no geometric ice climbers for the ring with the ethyl group because it's just the only group but on these two rings where there are two methyl groups, you can have either CIS or trans. So the methyl groups could be on the same side, say both wedge or we could have one wedge and one dash, which would be trans. Right? So let's draw all those possibilities. So, we have both of our methyl groups will be on neighboring carbons and we'll make it sis. Or we could have the neighboring methods be trans. one wedge, 1. Okay, similarly, I could have these metals on opposite carbons across from the ring. Both wedge, which would be Cis or one wedge one dash, which would be trans. And again, we said there are no geometric numbers for this one. So it will still look like this. And let's go ahead and just name all of these quickly. So we said this one assists 1, 2 dimethyl cyclo butane. Right? They're all going to have the root name cyclo butane and this one is trans, but the rest is the same one to die metal cyclo beauty. Then we have again, another cyst structure sis dimethyl cyclo beauty mean, And trans. 1, 3 die missile cyclo beauty mean. And lastly, we have our ethyl group since it's the only substitution group on this ring, we don't technically have to put a number that the carbon is on because we always want a number closest to our substitution group. So technically it would be one. But it doesn't matter where we put it. So we can just write ethel cyclo Beauty. All right. So those are all the customers for the cyclo butane With the Formula C6 H 12. I hope this video is helpful. And thanks for watching

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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

Naming Cycloalkanes

Organic Chemistry

4. Alkanes and Cycloalkanes

Naming Cycloalkanes

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4:37 minutes

Problem 33b

Textbook Question

Draw and name the six isomeric cyclopentanes of molecular formula C₇H₁₄. These will include four constitutional isomers, of which two show geometric (cis-trans) stereoisomerism.

Verified step by step guidance

Step 1: Understand the molecular formula C7H14. This indicates a degree of unsaturation, which suggests the presence of a ring or double bond. Since the problem specifies cyclopentanes, the structure will include a five-membered ring with two additional carbon atoms attached as substituents.

Step 2: Begin by drawing the parent structure, cyclopentane, and systematically add the two substituents (methyl groups) in different positions to create the four constitutional isomers. For example, place both methyl groups on the same carbon (1,1-dimethylcyclopentane), or on adjacent carbons (1,2-dimethylcyclopentane), or on carbons separated by one or more carbons (1,3-dimethylcyclopentane and 1,4-dimethylcyclopentane).

Step 3: Identify which of these constitutional isomers can exhibit geometric (cis-trans) stereoisomerism. Geometric isomerism arises when there is restricted rotation, such as in a ring, and substituents are positioned differently in 3D space. For example, in 1,2-dimethylcyclopentane, the two methyl groups can be on the same side of the ring (cis) or on opposite sides (trans).

Step 4: Draw the structures of the cis and trans isomers for the compounds that exhibit geometric isomerism. Clearly indicate the spatial arrangement of the substituents (e.g., using wedge and dash bonds to show 3D orientation).

Step 5: Name each isomer according to IUPAC nomenclature rules, ensuring that the substituents are numbered to give the lowest possible locants. For example, 1,1-dimethylcyclopentane, cis-1,2-dimethylcyclopentane, trans-1,2-dimethylcyclopentane, etc. Verify that all six isomers (four constitutional isomers and two stereoisomers) are accounted for.

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Key Concepts

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

Isomerism

Isomerism refers to the phenomenon where compounds have the same molecular formula but different structural arrangements or spatial orientations. In organic chemistry, isomers can be classified into constitutional isomers, which differ in the connectivity of atoms, and stereoisomers, which have the same connectivity but differ in the arrangement of atoms in space.

Cyclopentane Structure

Cyclopentane is a cyclic hydrocarbon with the formula C5H10, consisting of five carbon atoms arranged in a ring. When considering isomers of C7H14, cyclopentane can serve as a base structure, allowing for the addition of two carbon atoms in various configurations, leading to different isomeric forms, including branched and cyclic structures.

Geometric Isomerism

Geometric isomerism, also known as cis-trans isomerism, occurs in compounds with restricted rotation around a bond, typically a double bond or a ring structure. In the context of cyclopentanes, this type of isomerism arises when substituents on the cyclopentane ring can be arranged in different spatial orientations, leading to distinct isomers that can have different physical and chemical properties.

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