Naming Ethers - IUPAC Nomenclature With Branching, Organic Chemistry Practice Problems
Summary
TLDRThis 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
- đ Naming ethers involves both common and IUPAC names.
- đ Common names are determined by the groups attached to the oxygen, such as methyl and ethyl groups.
- đ For common names, the groups are alphabetized, e.g., ethyl methyl ether.
- đŹ The IUPAC naming involves identifying the longest carbon chain and treating the remaining group as a substituent.
- đ Methoxy and ethoxy groups are common substituents in ethers.
- đ Example: CH3-O-CH2CH3 is methoxyethane in IUPAC naming.
- đ For symmetrical ethers like diethyl ether, the IUPAC name remains simple: ethoxyethane.
- đ Priority in numbering the chain is given to achieve the lowest possible numbers for substituents.
- đ Alphabetization is key in naming, for instance, ethoxy comes before methyl in the name 3-ethoxy-2-methylpentane.
- đ§Ș 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
đŹ 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.
đ 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.
đ§Ș 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.
Mindmap
Keywords
đĄEthers
đĄCommon Name
đĄIUPAC Name
đĄMethoxy Group
đĄEthoxy Group
đĄAlphabetize
đĄLongest Chain
đĄParent Chain
đĄSubstituent
đĄDiethyl Ether
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
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