Naming Epoxides and Oxiranes using IUPAC Nomenclature

Summary

In this educational video, Leah4Sci.com explains how to name epoxides, also known as oxiranes, using two methods: the IUPAC epoxy prefix and the oxirane suffix. She demonstrates with examples, including substituted epoxides and those in larger molecules, providing clear guidelines for organic chemistry students.

Takeaways

• 🧪 Epoxides, also known as oxiranes, are heterocyclic compounds with a three-membered ring consisting of two carbons and one oxygen atom.
• 🔍 There are two methods for naming epoxides: using the prefix 'epoxy' following IUPAC rules, and using the suffix 'oxirane'.
• 📝 The 'epoxy' method involves identifying the parent chain and numbering to give the lowest possible number to the epoxide group, resulting in a name like '1,2-epoxyethane'.
• 🔑 When using the 'oxirane' method, the epoxide itself is considered the parent chain, and substituents are named and placed before 'oxirane', such as 'methyloxirane'.
• 🌟 For simple epoxides without substituents, the molecule can be simply referred to as 'oxirane'.
• 📐 In the IUPAC system, the longest carbon chain is identified as the parent, and the numbering is chosen to give the lowest numbers to the substituents.
• ✂️ For substituted epoxides, the numbering system prioritizes the position of the epoxide group and the substituents' alphabetical order in the final name.
• 🔄 In more complex molecules, the epoxy method is recommended for clarity, involving identifying the longest parent chain and appropriately numbering and naming substituents.
• 🔄 When an epoxide is part of a ring, the ring is treated as the parent chain, and the epoxide group is named with its position, like '1,2-epoxycyclohexane'.
• 📚 Leah offers an ebook titled '10 Secrets to Acing Organic Chemistry' and online tutoring services for those struggling with the subject.
• 📢 The video encourages viewers to like, share, subscribe, and reach out for questions or comments, indicating an interactive and supportive community.

Q & A

What is an epoxide?

An epoxide, also known as oxirane, is a heterocyclic compound with two carbons bound to an oxygen, forming a three-membered ring that includes a non-carbon atom.

What are the two methods for naming epoxides mentioned in the script?

The two methods for naming epoxides are using the prefix 'epoxy' following the IUPAC rules, and using the suffix 'oxirane' at the end of the molecule's name.

How do you name an epoxide using the 'epoxy' prefix method?

When using the 'epoxy' prefix method, you identify the parent chain, number the carbons to give the lowest possible number to the oxygen atoms, and then prefix the molecule's name with '1,2-epoxy' or '1,3-epoxy' depending on the position of the oxygen atoms.

What is the basic naming structure for an epoxide using the 'oxirane' method?

For the 'oxirane' method, if there are no substituents, the epoxide can simply be named 'oxirane'. If there are substituents, they are named before 'oxirane', for example, 'methyloxirane' for a methyl substituent.

How do you handle substituents when naming an epoxide using the IUPAC system?

In the IUPAC system, you identify the longest carbon chain, number it to give the lowest possible numbers to the substituents, and then include the substituents' names and positions in the final name, such as '2,3-epoxy-2-methylbutane'.

What is the significance of numbering from the right in the IUPAC method for a substituted epoxide?

Numbering from the right in the IUPAC method is chosen to give the lowest possible numbers to the substituents, which in the case of the script, allows the methyl group to have a lower number than if numbered from the left.

How do you name an epoxide when it is part of a larger molecule?

For larger molecules with an epoxide, you identify the longest parent chain, number from the direction that gives the lowest numbers to all substituents, and then include the substituents' names and positions in alphabetical order, such as '1-chloro-2,3-epoxy-7-methylnonane'.

What is the unique numbering system for the 'oxirane' method when there are multiple substituents?

In the 'oxirane' method with multiple substituents, oxygen is given number 1, the more substituted or higher priority carbon is given number 2, and the second carbon in the ring is number 3. The substituents are then named and numbered accordingly, such as '2,2,3-trimethyloxirane'.

How is an epoxide named when it appears on a ring?

When an epoxide appears on a ring, the parent chain is identified, and the ring is treated as part of the name, such as 'epoxycyclohexane'. The numbering ensures that both carbons holding the oxygen have sequential numbers.

What resources does Leah4Sci offer for students struggling with organic chemistry?

Leah4Sci offers an ebook titled '10 Secrets to Acing Organic Chemistry', online tutoring services, and a Facebook page for questions and interactions at Facebook.com/Leah4Sci.

How can viewers engage with Leah4Sci's content and stay updated?

Viewers can give the video a thumbs up, share it with friends, subscribe to the channel to stay updated on new videos, and leave comments or contact Leah4Sci through the provided Facebook page for any questions.

Outlines

00:00

🧪 Naming Epoxides in Organic Chemistry

In this segment, Leah from Leah4Sci.com introduces the concept of epoxides, also known as oxiranes, which are heterocyclic compounds formed by two carbons and an oxygen. She explains two methods for naming these compounds: the IUPAC rule using the prefix 'epoxy' and the 'oxirane' suffix method. Leah demonstrates how to apply these methods to simple and substituted epoxides, including examples with methyl substituents and more complex structures. She emphasizes the importance of identifying the parent chain, numbering the carbons to give the lowest possible numbers to substituents, and using prefixes and suffixes to denote the position and type of substituents. The segment concludes with a recommendation to use the epoxy method for larger molecules and a brief mention of how to handle epoxides in rings.

05:01

📚 Resources for Organic Chemistry Success

Leah offers additional support for those struggling with organic chemistry by promoting her ebook, '10 Secrets to Acing Organic Chemistry,' which can be downloaded via a link provided. She also invites viewers to explore her website for information on online tutoring services. Leah encourages engagement by asking viewers to like the video, share it with friends, and subscribe to her channel to stay updated on related content. She provides a direct link to her Facebook page for further interaction and questions, ensuring that viewers have multiple avenues to connect and learn more about the subject.

Keywords

💡Epoxides

Epoxides are organic compounds where an oxygen atom is bound to two carbon atoms, forming a three-membered ring structure. This heterocyclic compound is a focus of the video, where Leah discusses their naming conventions in organic chemistry. Epoxides are referred to by different names like oxirane, which signifies their structure and properties.

💡Oxirane

Oxirane is another name for an epoxide, specifically referring to the three-membered ring containing an oxygen atom. In the video, Leah explains that oxirane can be used as a suffix when naming epoxides, especially when there are no other substituents on the molecule. For instance, a simple epoxide with no other groups attached can be named oxirane.

💡Heterocyclic compound

A heterocyclic compound is a ring structure that contains at least one atom that is not carbon. In the context of the video, epoxides are heterocyclic compounds because their ring structure includes an oxygen atom along with carbon atoms. This concept is fundamental to understanding why epoxides behave differently than purely carbon-based rings.

💡IUPAC naming

The International Union of Pure and Applied Chemistry (IUPAC) naming system provides standardized rules for naming chemical compounds. Leah explains two IUPAC methods for naming epoxides: using the prefix 'epoxy' and the suffix 'oxirane.' These methods ensure clarity and uniformity in chemical nomenclature.

💡Prefix epoxy

The prefix 'epoxy' is used in the IUPAC naming system to denote the presence of an epoxide group within a molecule. Leah demonstrates this with examples like 1,2-epoxyethane, where 'epoxy' indicates the oxygen is bonded to the first and second carbons of an ethane chain.

💡Suffix oxirane

The suffix 'oxirane' is another IUPAC naming convention for epoxides. Leah explains that when using this method, the entire epoxide ring is treated as the parent chain. For example, a simple epoxide is named oxirane, and if it has substituents like a methyl group, it becomes methyloxirane.

💡Parent chain

In organic chemistry nomenclature, the parent chain is the longest continuous chain of carbon atoms in a molecule. Leah highlights the importance of identifying the parent chain when naming epoxides, as it determines the base name of the compound, such as 'ethane' in 1,2-epoxyethane.

💡Substituents

Substituents are atoms or groups of atoms attached to the parent chain of a molecule. Leah discusses how substituents, such as methyl groups, affect the naming of epoxides. For instance, in methyloxirane, the methyl group is a substituent on the oxirane ring.

💡Numbering system

The numbering system in organic chemistry nomenclature assigns numbers to carbon atoms in the parent chain to indicate the positions of substituents or functional groups. Leah demonstrates how to number epoxides to ensure the lowest possible numbers for substituents, such as in 1,2-epoxypropane.

💡Epoxycyclohexane

Epoxycyclohexane is an epoxide where the epoxide group is attached to a cyclohexane ring. Leah explains that when naming such compounds, the cyclic nature of the parent chain is indicated by 'cyclo,' and numbering ensures the epoxide group is correctly positioned, leading to the name epoxycyclohexane.

Highlights

Introduction to epoxides, also known as oxiranes, as heterocyclic compounds with a non-carbon atom in the ring.

Two methods for naming epoxides: the epoxy prefix following IUPAC rules and the oxirane suffix.

Step-by-step guide on using the 'puzzle piece approach' for naming epoxides with the epoxy prefix.

Example of naming a standard epoxide as 1,2-epoxyethane using IUPAC nomenclature.

Naming a simple epoxide as oxirane when there are no substituents.

Demonstration of naming a substituted epoxide as 1,2-epoxypropane according to IUPAC rules.

Use of the term 'methyloxirane' for a substituted epoxide with a methyl group.

Explanation of numbering for a more complex substituted epoxide using IUPAC system.

Naming a complex epoxide as 2,3-epoxy-2-methylbutane, incorporating both numbering and substituents.

Oxirane method for naming complex epoxides with multiple substituents, such as 2,2,3-trimethyloxirane.

Recommendation to use the epoxy method for larger molecules with an epoxide.

Detailed example of naming a large molecule with an epoxide as 1-chloro-2,3-epoxide-7-methylnonane.

Guidance on naming epoxides that appear on a ring, such as epoxycyclohexane.

Offering of an ebook titled '10 Secrets to Acing Organic Chemistry' for further learning.

Promotion of online tutoring services for organic chemistry through Leah4Sci.com.

Encouragement to like, share, and subscribe for more related organic chemistry videos.

Invitation to ask questions or contact Leah through her Facebook page for further assistance.

Transcripts

Leah here from Leah4Sci.com. And in this video, I will show you how to name epoxides. Epoxides

are also known as oxirane and this refers to a molecule that has two carbons bound to

an oxygen forming a heterocyclic compound where hetero implies that you have a non-carbon

atom in your ring.

There are two ways to name epoxides both of which may show up in your organic chemistry

course. And so, I will show you how to use both methods. The first one is to use the

prefix epoxy when the following the IUPAC rule or my puzzle piece approach to naming.

And the second one is to use suffix oxirane at the end of your molecule.

We'll start with a standard epoxide drawing out the two carbon and oxygens in a ring.

Using my puzzle piece approach, we'll start by identifying and highlighting the parent

chain. I have two carbons in my parent chain giving me a first name of eth. I have only

single bonds giving me a last name of ane. And I have the epoxy group showing up attached

to both carbons 1 and 2 and so I get the prefix 1,2-epoxy. Putting the name together, I get

1,2-epoxyethane.

Using the oxirane method, given that there's nothing coming off of this epoxide, we can

simply call this oxirane.

Now, let's look at a substituted epoxide. For the IUPAC rules, I still identify and

highlight my parent chain. In this case, numbering so that the epoxide gets the lowest number

meaning, I start from the right. Having a total of three carbons in my parent chain

gives me a first name of prop. Having only single bonds gives me a last name of ane.

Once again, the oxygen is bound to carbons 1 and 2 giving me 1,2-epoxy. This gives me

a final name of 1,2-epoxypropane.

When using the oxirane method, I identify the entire epoxide as the parent chain and

simply call it oxirane. Since I have a methyl substituent, I simply throw the word methyl

in front of oxirane. Since I only have an option to connect methyl to one or the other

carbon, I don't have to specify which one and give it a final name of methyloxirane.

Let's look at an even more substituted example. Starting with the IUPAC system, I highlight

and identify my longest carbon chain. If I number from the left, I hit epoxide at 2.

If I number from the right, I also hit the epoxide at 2 but that methyl groups gets the

lower number. And so, I number from the right. Four carbons gives me a first name of but.

Only single bonds gives me a last name of ane. The oxygen is fused to carbons 2 and

3 giving me 2,3-epoxy and the methyl and carbon 2 gives me 2-methyl. Since E goes before M,

I have 2,3-epoxy-2-methylbutane.

Now, let's look at the same structure using the oxirane method. In this case, I have multiple

substituents so I do have to number the ring. You have a unique numbering system where oxygen

gets a number 1, number 2 is going to be the more substituted or higher priority substituted

carbon of the oxirane and then 3 is the second carbon in the ring. In this case, I have three

methyl groups, two coming off of carbon 2 and one coming off of carbon 3, that gives

me 2,2,3-trimethyl followed by the suffix oxirane.

When you have a larger molecule with an epoxide, I recommend sticking with the epoxy method.

In this case, I first identify my longest parent chain and recognize that it's the branch

going down rather than just a methyl group because I have more carbons going that way.

I start numbering from the left because that is where I give the lowest number 2 all substituents.

A total of 9 carbons gives me a first name of non. Only single bonds gives me a last

name of ane. I have chlorine on carbon 1 giving me the prefix of 1-chloro. I have an epoxide

on carbons 2 and 3 giving me 2,3-epoxy. And the methyl group on carbon 7 giving me 7-methyl.

Arranging the substituents in alphabetical order, I have C followed by E followed by

M for a final name of 1-chloro-2,3-epoxy-7-methylnonane.

When you're epoxide shows up on a ring, you treat it the same way. In this case, the parent

chain has a six carbon ring. Six gives me a first name of hex. Only single bonds gives

me a last name of ane. And the fact that it's a ring gives me cyclo. When numbering, make

sure that both carbons holding the oxygen have sequential numbers. You can choose to

go clockwise or counterclockwise. The epoxide shows up on carbons 1 and 2 giving me 1,2-epoxy.

However, since there are no other substituents, the numbers are understood and I don't have

to include them. This gives me a final name of epoxycyclohexane.

Are you struggling with organic chemistry? Are you looking for information to guide you

through the course and help you succeed? If so, download my ebook, 10 Secrets to Acing

Organic Chemistry using the link below or visit Leah4Sci.com/OrgoSecrets. For information

regarding online tutoring, visit Leah4Sci.com/OrgoTutor.

If you enjoyed this video, please give it a thumbs up and even share it with a friend

or two. If you have any questions regarding this video, leave a comment below or contact

me through my Facebook page at Facebook.com/Leah4Sci.

There will be many related videos posted over the course of the semester so go ahead and

click the subscribe button to insure that you don't miss out