Ch. 4 - Alkanes and CycloalkanesWorksheetSee all chapters
All Chapters
Ch. 1 - A Review of General Chemistry
Ch. 2 - Molecular Representations
Ch. 3 - Acids and Bases
Ch. 4 - Alkanes and Cycloalkanes
Ch. 5 - Chirality
Ch. 6 - Thermodynamics and Kinetics
Ch. 7 - Substitution Reactions
Ch. 8 - Elimination Reactions
Ch. 9 - Alkenes and Alkynes
Ch. 10 - Addition Reactions
Ch. 11 - Radical Reactions
Ch. 12 - Alcohols, Ethers, Epoxides and Thiols
Ch. 13 - Alcohols and Carbonyl Compounds
Ch. 14 - Synthetic Techniques
Ch. 15 - Analytical Techniques: IR, NMR, Mass Spect
Ch. 16 - Conjugated Systems
Ch. 17 - Aromaticity
Ch. 18 - Reactions of Aromatics: EAS and Beyond
Ch. 19 - Aldehydes and Ketones: Nucleophilic Addition
Ch. 20 - Carboxylic Acid Derivatives: NAS
Ch. 21 - Enolate Chemistry: Reactions at the Alpha-Carbon
Ch. 22 - Condensation Chemistry
Ch. 23 - Amines
Ch. 24 - Carbohydrates
Ch. 25 - Phenols
Ch. 26 - Amino Acids, Peptides, and Proteins

Ringed structures are easy to name, you just need to use a new prefix (aka –cyclo)!

Hint: Benzene and a cyclohexane are NOT the same thing. Remember, benzene has double bonds in it!

Understanding Cycloalkanes

Concept #1: How to find the root name for cycloalkanes 

Transcript

So now we're just going to start layering stuff onto these alkanes and making the names more complex. Let's talk about what happens when you have a ring structure.
Cycloalkanes are the name given to any time that you have a ring inside of your alkane. We're going to start off with the easy ones, which is just monocyclic compounds. Monocyclic just means one ring. These are easy. All we're going to do is we're just going to attach cyclo- to the beginning of the root chain. All of the sudden hexane becomes cyclohexane if it's a ring.
The root is assigned to the portion of the alkane with the greater number of carbons. Now where this comes into play is that usually, it's really obvious which one is bigger or which one is going to get the root name, but sometimes it's not as obvious, meaning that sometimes you have both a long chain and a ring on the same structure. Most of the time it's just going to be either a chain or it's going to be a ring, but sometimes some structures combine both.
What do we do if we combine both? Then what we want to do is we want to give the part with the greater number of chains the root. 

In general, we assign the root name to the portion of the alkane that has the greater number of carbons

Example #1: Determine the root carbon name for the following structure 

Example #2: Determine the root carbon name for the following structure 

Numbering Monocyclic Cycloalkanes

If you only have one substituent on your ring, the numerical location is unnecessary! 

Concept #2: Why it is okay to omit a single location for monocyclics 

Transcript

Then lastly, if there's only one substituent on your ring. Let's say you have a ring and you have one thing coming off of it. The location of that thing can be omitted.
How does that make sense? Well, because if you have a chain – let me give you an example chain. Obviously, this is like the ugliest chain ever. I didn't even do the zigzags. But if you have a chain and you add one thing to it, that thing could be in a lot of different places. It could be there or I could erase it and I could put it there or I could erase and I could put it right at the end. Those are all different possibilities of where that stick could be. Do you just see how I'm saying that the location is going to matter? That is a different location than that.
But if I have a ring and I put it here, that's the same thing as if I put it here and that's the same thing as if I put it here. All of them are the same because the ring I can rotate as much as I want, whereas the chain, if I put it in the middle, it's stuck in the middle. It's never going to go to the end. Does that kind of make sense? For a chain, you always have to say the location. Always note location. But for a ring, location can be omitted. Does that make sense?
Now, this is only true if I have one group. If I have more than one branch, let's say I have two branches, now you need to say what the locations are. Why? Because that is going to be a very much different structure than that. And that's going to be a different structure than that. So then once I have two things, it breaks that rule. I'm just trying to say if you only have one thing coming off of your ring, many times that location will be omitted. Does that make sense? Cool. 

Time to complete those names. Let's give it a try.

Example #3: Name the following alkane 

Example #4: Name the following alkane 

Great job! Did you remember to include the location for the first example? Remember, that location is not optional!

Introduction to Bicyclics

Bicyclics are also forms of cycloalkanes, but since they are not monocyclic, they have completely different rules for naming! (See next topic)

Concept #3: What is a bicyclic molecule? 

Transcript

Now I just want to introduce bicyclic. I'm not going to rigorously teach you how to name them here. In fact, I'm not going to teach you how to name them unless your professor specifically asks because bicyclics are kind of iffy. Some professors want you to know them, some professors don't. But I'm just going to teach you – no matter what you should know the basics of what a bicyclic is.
Bicyclics are composed of two distinct rings attached along one bond. This would be an example of a bicyclic and it's made out of two cyclohexanes. The actual name for a bicyclic of two cyclohexanes is called a declin. Declin just equals cyclohexane bicyclic.
Some professors also take a special interest in declins and I will also be monitoring your class to see if I have to teach a separate section on declins as well. Some professors don't really care.
What's important is I just want you to know that a bicyclic, by the way, this dotted bond here is the same thing as a regular bond I'm just pointing out that this is the bond that's shared. That would be a bicyclic molecule.
Now a bridged compound is a type of bicyclic and it's actually composed of three compound rings attached by what we call two bridgehead – I know this is getting a little weird – bridgehead atoms.
Here's an example. This one's called norbornane. It's a very common – this is actually one of the most common bridge structures. And you're asking me, “Johnny, where are the three rings? I do not see three rings.” Well, there actually are. There's this main thing down here. That's actually just a weird way to draw cyclohexane. That's just a six-membered ring. Then I've got a five-membered ring if I go along one side and then up like that. That's one five-membered ring. Then it turns out that I have another five-membered ring if I go up the other side and up that thing.
This thing in the middle that I keep pointing to is called the bridge. It's like, I don't know, think about that you're walking over a bridge and you're going from one side of the molecule to the other, the atoms that attach all of those are called the bridgehead atoms. That's what I meant by two bridgeheads, so this is called a bridged compound.
These are going to get – we have different ways of naming bicyclics. These have a certain way of naming, but like I said, that's going to be a separate section that I teach you only if your professor requires that you know that. I just want you to be familiar with what a bridge is.
Awesome guys. So with that said let's go ahead and move on to the next topic. 

What is the systematic name for each of the following  compounds:
Write a bond-line formula for each of the following compounds: (k) 1,4-Dicyclopropylhexane  
Write a bond-line formula for each of the following compounds: (o) Cyclopentylcyclopentane  
Give systematic IUPAC names for each of the following:  
Give systematic IUPAC names for each of the following:  
Write the structure and give the IUPAC systematic name of an alkane or cycloalkane with the formulas (b) C6H12 that has only secondary hydrogen atoms.  
Draw each of the following compounds: (b) 1,2,3,4-Tetramethylcycloheptane
Write the structure and give the IUPAC systematic name of an alkane or cycloalkane with the formulas (c) C6H12 that has only primary and secondary hydrogen atoms.  
Ignoring compounds with double bonds, write structural formulas and give names for all of the isomers with the formula C5H10.  
Write a structural formula for each of the following compounds:  (c) 4-Isobutyl-1,1-dimethylcyclohexane
Write a structural formula for each of the following compounds: (d) sec -Butylcycloheptane 
Write a structural formula for each of the following compounds: (e) Cyclobutylcyclopentane 
Using the method outlined in Section 2.13, give an IUPAC name for each of the following alkyl groups, and classify each one as primary, secondary, or tertiary:
Please answer the following questions for the compound given below. a) Provide a name b) How many methine groups are there? c) Give the molecular formula for this compound d) For the number of Cs that you gave in the moleular formula for this problem, what is the maximum possible number of Hs? e) How many secondary Hydrogens are there? f) How many quaternary Cs are there?
Propylene is produced by cracking petroleum and is a very useful  precursor in the production of many useful polymers. Propylene has one constitutional isomer. Draw that isomer and identify its systematic name.
For the compound given below, provide a name.   
Which one is the molecular formula of a cyclohexyl group? a) C6H6 b) C6H5 c) C6H12 d) C6H11
Write the IUPAC name of the following line structure. Ignore R and S while naming.
Give the IUPAC name for the following compound:
The general molecular formula for alkanes is  CnH2n+2. What is the general molecular formula for: (a) Cycloalkanes 
In the box, give the  IUPAC name for the following hydrocarbon.
Draw the structure of the cycloalkane 1,4-dimethylcyclohexane. Include hydrogen atoms.
Draw the structure of the cycloalkane 1, 4-dimethylcyclohexane.
Select the correct IUPAC name for the following cycloalkane:
Select the correct IUPAC name for the following cycloalkane:
Name the following molecule:
Select the correct IUPAC name for the following cycloalkane:a) 1- methyl-2-methylcyclohexaneb) 1 - ethyl-2,2-dimethylcyclobutanec) 1- ethyl-2,3-dimethylcyclobutaned) 1,2-dimethyl-3-ethylcyclobutane
Click on the carbon atom that should be designated as #1 when naming this compound systematically. Give the systematic name for the compound. 
Draw the structure of (1,1-dimethylethyl)cyclopentane.
Using the IUPAC system, name the following molecules
The names provided are incorrect. Provide the correct IUPAC name in the space below.2-ethyl-2,4,6-trimethylheptane3-butyl-2,2-dimethylhexane1-cyclopropyl-3,4-dimethylcyclohexane
Give the IUPAC name for the following compound. a. 2-cyclohexybutane b. 1-cyclohexyl-1-methylpropane c. 1-methyl-1-cyclohexylpropane d. sec-butylcyclohexane e. isopropylcyclohexane
Give the IUPAC name for the following compound.
Give the IUPAC name for the following compound. a. 4-sec-butyl-2,3-dimethylheptane b. 2,3,5-trimethyl-4-propylheptane c. 4-pentyl-3-methylheptane d. 2,3,5-trimethyl-7-ethyloctane e. 4-sec-butyl-2, 3-dimethyloctane a. 1,2-diisobutyl-4,4-dimethylcyclohexane b. 4,5-diisobutyl-1,1-dimethylcyclohexane c. 1,2-diisopropyl-4,4-dimethylcyclohexane d. 3,4-diisobutyl-1,1-dimethylcyclohexane e. 3,4-disec-butyl-1,1-dimethylcyclohexane
Draw the structure of (1,1-dimethylethyl)cyclopentane.
Draw the structure for 1,3-dinitrocyclobutane. Use the shortcut tool for adding the nitro group.
Draw the structure of 1,1-dimethylcyclohexane.
Click on the carbon atom that should be designated as #1 when naming this compound systematically. Give the systematic name for the compound. Spelling and punctuation count! 
Provide an acceptable name for the compound shown below.
What is the IUPAC name of the following compound?
What is the IUPAC name for the compound shown below?
What is the IUPAC name of the following compound?
What is the IUPAC name for the compound shown below?
Select the correct IUPAC name for the following cycloalkane: a. 1-methyl-1-ethylcyclopropane b. 1-ethyl-1-methylcyclopropane c. 1,1-methylethylcyclobutane d. 1-ethyl-1-propylcycloputane
What is the IUPAC name for the compound shown below?
Name the following cycloalkane
Give the systematic name for the compound. Spelling and punctuation count!
Name the compound below: cis-1-ethylcyclobutane, trans-1-ethylcyclobutane 1-ethylbutane, 1-ethylcyclobutane
What is the lUPAC name for the compound shown below?
Click the "draw structure" button to activate the drawing utility.Enter the structure corresponding to the IUPAC name. 1-sec-butyl-3-isopropylcyclopentane
Name the following compound. Be sure to answer all parts. 
The following names are incorrect. Draw the structure of the compound and provide the correct IUPAC name. Molecule #1: 1, 3-dimethylcyclopropane 
What is the IUPAC name for the following alkane?
Name: Formula: C11H22
4-ethyl-1, 1-dimethylcyclohexane 
Name the following cycloalkane
What is the IUPAC name for the following alkane? 
What is the IUPAC name for the compound shown in the attached image?a. di(1,2-dimethyl)cycloheptaneb. 1,2,4,5-tetramethylcycloheptanec. 1,3,4,6-tetramethylcycloheptaned. 1,2,5,6-tetramethylcycloheptane 
Name the following cycloalkane
What the correct IUPAC name for the compound shown in the attached image?a. 2-bromo-1-ethyl-2-methylcyclopropaneb. 1-bromo-3-ethyl-1-methylcyclopropanec. 1-bromo-1-ethyl-2methylcyclopropaned. 1-bromo-2-ethyl-1-methylcyclopropane  
Name the following cycloalkane