Naming Ethers - IUPAC Nomenclature With Branching, Organic Chemistry Practice Problems

Summary

This educational video script delves into the nomenclature of ethers, both common and IUPAC names. It systematically explains how to identify and name ethers by recognizing the longest carbon chain and the substituents, such as methyl or ethyl groups. The script also covers the prioritization of functional groups like alcohols over ethers and provides examples to illustrate the naming process, including complex cases with multiple substituents and cyclic structures. It's a concise guide for understanding the principles of organic chemistry naming conventions for ethers.

Takeaways

• 📘 Naming ethers involves both common and IUPAC names.
• 🔍 Common names are determined by the groups attached to the oxygen, such as methyl and ethyl groups.
• 📝 For common names, the groups are alphabetized, e.g., ethyl methyl ether.
• 🔬 The IUPAC naming involves identifying the longest carbon chain and treating the remaining group as a substituent.
• 📊 Methoxy and ethoxy groups are common substituents in ethers.
• 📑 Example: CH3-O-CH2CH3 is methoxyethane in IUPAC naming.
• 🔄 For symmetrical ethers like diethyl ether, the IUPAC name remains simple: ethoxyethane.
• 🔗 Priority in numbering the chain is given to achieve the lowest possible numbers for substituents.
• 🌐 Alphabetization is key in naming, for instance, ethoxy comes before methyl in the name 3-ethoxy-2-methylpentane.
• 🧪 Functional groups like alcohols and halides can change the priority in naming, such as 4-bromo-3-methoxy-2-pentanol.

Q & A

What is the common name of the ether with the structure CH3-O-CH2CH3?

The common name of the ether with the structure CH3-O-CH2CH3 is ethyl methyl ether.

How is the IUPAC name of the ether CH3-O-CH2CH3 derived?

The IUPAC name is derived by identifying the longest chain and naming the ether as a substituent. For CH3-O-CH2CH3, the longest chain has two carbons (ethane) and the ether group is methoxy, so the IUPAC name is methoxyethane.

What is the common name for an ether with a butyl group on the left and an ethyl group on the right?

The common name for an ether with a butyl group on the left and an ethyl group on the right is butyl ethyl ether.

How do you name the ether with the structure C4H9-O-C2H5 using IUPAC nomenclature?

Using IUPAC nomenclature, the longest chain is butane, and the ether group is ethoxy. The name is 1-ethoxybutane.

What is the common name for an ether with two ethyl groups on both sides?

The common name for an ether with two ethyl groups on both sides is diethyl ether.

How is the IUPAC name for diethyl ether derived?

The IUPAC name for diethyl ether is derived by treating one ethyl group as a substituent. The name is ethoxyethane.

What is the common name for an ether with an isopropyl group on the left and an ethyl group on the right?

The common name for an ether with an isopropyl group on the left and an ethyl group on the right is ethyl isopropyl ether.

How do you name the ether with a structure including an ethoxy group on a propane chain using IUPAC nomenclature?

Using IUPAC nomenclature, the longest chain is propane, and the ether group is ethoxy attached to carbon 2. The name is 2-ethoxypropane.

How do you name an ether with a five-carbon chain, an ethoxy group on carbon 3, and a methyl group on carbon 2?

You name the ether by counting the longest chain to give the substituents the lowest numbers. The name is 3-ethoxy-2-methylpentane.

How do you name a molecule with both an ether and an alcohol group, with the alcohol having higher priority?

You give the alcohol the lowest number and name the substituents in alphabetical order. For example, if the molecule has a bromo group on 4, a methoxy group on 3, and an alcohol on 2, the name is 4-bromo-3-methoxy-2-pentanol.

Outlines

00:00

🔬 Naming Ethers: Common and IUPAC Nomenclature

In this video, we focus on naming ethers using both common names and IUPAC names. We begin with an example where CH3-O-CH2CH3 is analyzed. The common name is derived by identifying the methyl and ethyl groups and alphabetizing them to get ethyl methyl ether. For the IUPAC name, the longest chain is identified, and the substituent (methoxy group) is placed accordingly, resulting in methoxyethane. Additional examples are provided to illustrate the naming process for ethers with different substituents, including butyl ethyl ether (common name) and 1-ethoxybutane (IUPAC name). The video covers various ethers, explaining both common and IUPAC names, such as diethyl ether and ethoxyethane, and ethyl isopropyl ether and 2-ethoxypropane.

05:02

📚 Applying IUPAC Naming Rules to Complex Ethers

This section delves into more complex examples of naming ethers using IUPAC rules. A detailed step-by-step approach is provided to identify the longest carbon chain and correctly place substituents. For example, in a structure with an ethoxy group and a methyl group, the correct IUPAC name is determined by counting carbon chains to give the lowest substituent numbers, resulting in 3-ethoxy-2-methylpentane. The video also addresses ethers with additional functional groups like alcohols and halides, prioritizing the alcohol group in naming and resulting in names like 4-bromo-3-methoxy-2-pentanol. Finally, it covers cyclic ethers and complex structures with multiple ether groups, explaining the naming conventions for these compounds.

10:03

🧪 Advanced Ether Naming with Multiple Substituents

In the final part of the video, we tackle the naming of ethers with multiple substituents and cyclic structures. Examples include cyclopentyl methyl ether (common name) and methoxycyclopentane (IUPAC name). Another example discusses a six-carbon ring with an ethoxy group, named as cyclohexyl ethyl ether (common name) and ethoxycyclohexane (IUPAC name). The video explains how to name structures with two ethers, such as 1,2-dimethoxyethane, and more complex molecules like those with multiple ethoxy groups, resulting in names like 1,6-diethoxynonane. The tutorial provides comprehensive guidelines for naming various ethers, ensuring a clear understanding of both common and IUPAC nomenclature.

Keywords

💡Ethers

Ethers are a class of organic compounds characterized by an oxygen atom connected to two alkyl or aryl groups. In the video, the focus is on naming ethers using both common and IUPAC nomenclature systems, emphasizing their structural composition.

💡Common Name

The common name of an ether is derived by naming the two alkyl groups attached to the oxygen atom, followed by the word 'ether'. For example, 'ethyl methyl ether' is used for an ether with an ethyl group and a methyl group. This naming is less systematic compared to the IUPAC method.

💡IUPAC Name

The IUPAC name is a systematic way of naming chemical compounds. For ethers, it involves identifying the longest carbon chain as the parent hydrocarbon and naming the alkoxy group as a substituent. For instance, 'methoxyethane' refers to an ether with a methoxy group (O-CH3) attached to an ethane chain.

💡Methoxy Group

A methoxy group (O-CH3) is a substituent consisting of a methyl group bonded to an oxygen atom. In the video, the methoxy group is frequently mentioned as part of the IUPAC naming for ethers, such as '1-methoxyethane'.

💡Ethoxy Group

An ethoxy group (O-CH2CH3) is a substituent comprising an ethyl group attached to an oxygen atom. It is used in the IUPAC names of ethers, such as '1-ethoxybutane', where the ethoxy group is bonded to a butane chain.

💡Alphabetize

Alphabetizing refers to arranging substituents in alphabetical order when naming compounds. This is essential in both common and IUPAC nomenclature. For instance, 'ethyl methyl ether' is named by alphabetizing 'ethyl' before 'methyl'.

💡Longest Chain

The longest chain refers to the longest continuous carbon chain in a molecule, which serves as the parent hydrocarbon in IUPAC naming. In the video, identifying the longest chain is crucial for naming ethers, such as determining 'ethane' as the parent chain in 'methoxyethane'.

💡Parent Chain

The parent chain is the longest continuous chain of carbon atoms in a molecule, which forms the base name in IUPAC nomenclature. For example, in '1-ethoxybutane', 'butane' is the parent chain. Identifying the parent chain helps in systematic naming of ethers.

💡Substituent

A substituent is an atom or group of atoms that replaces hydrogen in a hydrocarbon chain. In the context of ethers, substituents like methoxy (O-CH3) and ethoxy (O-CH2CH3) are attached to the parent chain. Proper identification and naming of substituents are essential for IUPAC names.

💡Diethyl Ether

Diethyl ether is a common ether where two ethyl groups are attached to an oxygen atom. Its common name reflects the identical alkyl groups. The IUPAC name 'ethoxyethane' also denotes the presence of ethoxy groups attached to an ethane chain. Diethyl ether is frequently used as a solvent and has significant historical importance in anesthesia.

Highlights

Naming ethers: Focus on common names and IUPAC names for ethers.

Example 1: CH3-O-CH2CH3 is known as ethyl methyl ether (common name).

IUPAC naming: Methoxyethane is derived from identifying the longest chain and substituent.

Example 2: CH3CH2-O-CH2CH2CH2CH3 is butyl ethyl ether (common name).

IUPAC name for Example 2: 1-ethoxybutane, identifying the longest chain and ethoxy group.

Example 3: (CH3CH2)2O is called diethyl ether, emphasizing identical groups.

IUPAC name for Example 3: Ethoxyethane, highlighting identical sides.

Example 4: CH3CH2-O-CH(CH3)2, common name is ethyl isopropyl ether.

IUPAC naming for Example 4: 2-ethoxypropane, identifying chain and substituent position.

Naming challenge with longer chains: 3-ethoxy-2-methylpentane.

Priority group identification: Alcohols prioritized over ethers for naming.

Naming example with alcohol and ether: 4-bromo-3-methoxy-2-pentanol.

Cycloalkane example: Cyclopentyl methyl ether with IUPAC name methoxycyclopentane.

Naming cyclic ethers: Cyclohexyl ethyl ether and its IUPAC name ethoxycyclohexane.

Multiple ethers example: 1,2-dimethoxyethane for two methoxy groups on ethane.

Complex molecule example: 1,6-diethoxynonane with multiple ethoxy groups.

Transcripts

in this video we're going to focus on

naming ethers

we're going to talk about the common

names and also

the iupac names so let's start with this

example

let's say if we have ch3

o

ch2 ch3

what is the common name of this

particular ether

so notice that we have

a methyl group on the left

and on the right

we have an ethyl group

if you recall methane is associated with

one carbon

ethane is for two carbons propane is for

three

butane is four pentane is five hexane is

six

heptane is seven

octane is eight nine is nine dictates

ten

so we have two carbons on the right so

it's an ethyl group one on the left

methyl

and to put it together we need to

alphabetize it so it's called

ethel

method

ether this is the common name

now what about the iupac name

what is it for this particular example

well let's redraw it

so the longest structure or the longest

chain

is the two carbons on the left

so i'm going to write it like

that and then i'm going to draw this as

a substituent

so we have an o ch3 group

so notice that on carbon 1

we have this group which is called a

methoxy group as a substituent

so it's one methoxy ethane or simply

methoxy ethane

the ethane is the parent chain of the

two carbons on the

left so this is the iupac name

for this particular ether

let's try another example

let's name this particular ether

feel free to pause the video and work on

this example

on the right we have two carbons on the

left we have four carbons

so we have a butyl group on the left

and an ethyl group on the right

so it's already in alphabetical order so

it's called butyl ethyl

ether

now that's the common name but what

about the iupac name

so let's redraw

so here's the longest chain

it's four carbons

and the

substituent is this portion

of the molecule

och3 is known as methoxy

as a substituent

because it has only a methyl group here

we have an ether group attached to it so

this is called ethoxy

so it's one ethoxy

and the parent name is butane it's a

four carbon alkane so one ethoxybutane

that's the iupac name for that example

now how about this example

how can we name this particular ether

so notice that we have an ethyl group on

both sides

so we have two ethyl groups it's not

called ethyl ethyl ether but it's simply

diethyl ether

so that's the common name

now for the iupac name

we're going to treat one side as a

substituent

so i'm going to write it as och2ch3

so once again this is ethoxy and it's on

carbon 1 but if it was here this would

be carbon 1 so

for two carbon chain

no matter where you put the ethoxy group

it's going to be on carbon one so you

could just call it ethoxy

ethane

and that's all you got to do for this

one

here's another one that we could try

what's the common name for this

particular ether

now on the right we have an ethyl group

on the left we have three carbons but

based on the way it's connected this is

an isopropyl group

so e comes before i

so this is ethyl

isopropyl

ether

now what about the

iupac name

what is it for this particular molecule

so i'm going to redraw

first i'm going to draw these three

carbons because

that's the longest chain so 2 3

and on carbon 2 i'm going to draw the

ethoxy group

so i'm going to rewrite it like this

so you can clearly see that the ethoxy

group

is on carbon two

so it's two ethoxy

and for a three carbon alkane it's

propane

so two ethoxy propane that's the iupac

name for this ether

now what about this one

let's focus only on

the iupac name

what is the iupac name for this

structure

so first we need to identify the longest

chain

should we count it from right to left or

left to right

if we count it from left to right

we're gonna have two substituents

at three and four we have an ethoxy

group at three

and a methyl at four if we count it from

right to left

the methyl is going to be on carbon 2

instead of carbon 4.

so

you want to count in

the direction that's going to give you

the lower numbers so we want to count

that way

so now we got to alphabetize it

which one comes first ethoxy or methyl

e comes before m so

we're gonna put the ethoxy group first

so it's three ethoxy

dash two methyl

and four five carbon chain

it's pentane

so this is the answer

now what about this one

let's say if we have

not only an ether but

also an alcohol group

also a halide how can we name this

particular compound

so which group has more priority the

alcohol or the ether

alcohols typically have more priority

than ethers

so to name it

we're going to give the oh the lower

number so we're going to count it from

right to left

now we have a bromo group on 4 and a

methoxy group on 3. so br is going to be

written first because it has the lower

alphabet

so it's four bromo

dash three

dash methoxy instead of ethoxy

because

the ether has a methyl group

and then dash two

we have a five carbon chain so instead

of saying pentane it's going to be

pentanol

the oh is on carbon two

so that's it four bromo three 3-methoxy

2-pentanol

now what about this example

how can we name

this particular ether let's start with

the common name

so on the right we have a methyl group

on the left we have a cyclopentyl group

because it has a ring with five carbons

and c comes before m

so it's going to be called cyclopentyl

methyl

ether

now what about the iupac name

well first we need to identify the

longest chain

and it's clearly

the five carbon ring

so that's going to be called

cyclopentane

and this is the substituent which is

known as methoxy so it's simply called

methoxy

cyclopentane well that is not

cyclopentane

i forgot the y

here it is

try this one

let's say if we have a six carbon ring

and an och2 ch3 group

so let's start with the common name

on the right we have an ethyl

on the left we have a cyclohexyl group

so c

comes before e

in the alphabet so

it's cyclo

hexo

ethyl

ether

now for the iupac name

the six carbon ring is the longest chain

so that's gonna be called cyclo

hexing and

the substituent is ethoxy

and it's automatically on carbon one so

we just write it as ethoxy

cyclohexane

now what if you have a molecule

that looks like this

how would you name it

so we have two ethers

so i'm going to redraw

so what is the iupac name

for this compound

so this is a substituent that's methoxy

we have another methoxy group one of

them is on carbon one the others on

carbon two

now the longest chain is the two carbon

chain in the middle which is ethane

and since we have two methoxy groups

we're gonna call it dimethoxy so it's

one two

dash

dimethoxy

ethane

now let's try one last example similar

to this one

how would you name this ether

so this is a ethoxy group and here we

have another epoxy

group now we want to count it from left

to right not right to left so we can get

the lower numbers

so we want to make this 1 2 3 4

5 6 7

8 9. the longest chain is 9 which is a

we have a ethoxy group at one and six so

it's going to be one comma six

dash

die ethoxy

none

and that's it so now you know how to

name ethers