Esters are organic compounds characterized by the presence of an oxygen atom bonded to an alkyl group and a carbon chain that includes a carbonyl group (C=O). This structure is essential in defining esters and differentiating them from other organic compounds. When it comes to naming esters, a specific convention is followed. The carbon chain that contains the carbonyl group is named similarly to a carboxylic acid, but with a crucial modification: the suffix changes from "oic acid" to "oate." This alteration signifies that the compound is now an ester rather than a carboxylic acid. In the naming process, the longest carbon chain is identified as the parent chain, and any substituents attached to this chain are also considered. The final name of the ester will reflect both the parent chain and the substituents, ensuring clarity in its identification. For example, if the parent chain is derived from acetic acid, the ester would be named acetate. Understanding this naming convention is vital for accurately identifying and communicating about esters in organic chemistry.
16. Carboxylic Acids and Their Derivatives
Naming Esters
16. Carboxylic Acids and Their Derivatives
Naming Esters: Videos & Practice Problems
Esters are organic compounds characterized by an alkyl group connected to an oxygen atom and a carbon chain with a carbonyl group. Their naming involves modifying the carboxylic acid suffix "oic acid" to "ate." Common naming follows a similar pattern, starting with the alkyl group followed by the carbon chain name, ending in "ate." For example, a propyl group attached to a valerate results in "propyl valerate." When multiple substituents are present, they are named in alphabetical order, with prefixes indicating quantity, such as di- for two or tri- for three.
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IUPAC Rules for Naming Esters Concept 1
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59sIUPAC Rules for Naming Esters Concept 1 Video Summary
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IUPAC Rules for Naming Esters Example 1
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3mIUPAC Rules for Naming Esters Example 1 Video Summary
To systematically name an ester, we follow a structured approach that involves identifying the alkyl group and the carbonyl chain. First, we determine the alkyl group connected to the oxygen atom. In this case, the alkyl group consists of two carbon atoms, which is named ethyl.
Next, we identify the carbonyl group, which is the functional group characteristic of esters. The carbon chain connected to the carbonyl group is then assessed for its length. Starting from the carbonyl carbon, we number the chain: 1, 2, 3, 4. The carbonyl carbon is considered carbon number one.
We also need to identify any substituents on the carbon chain. In this example, there is a methyl group located on carbon number three. When there are multiple identical substituents, we use prefixes such as 'di' for two, 'tri' for three, and 'tetra' for four. Here, we only have one methyl group.
When naming the substituents, we list them in alphabetical order, disregarding any numerical prefixes. We separate numbers with commas and use dashes to separate letters from numbers, while letters are not separated from each other. Additionally, the alkyl group name connected to the oxygen is written with spaces.
Putting this all together, we start with the alkyl group, which is ethyl (written with spaces). Next, we note the methyl substituent on carbon number three, leading to '3-methyl'. The carbon chain is a four-carbon chain, which corresponds to butanoic acid. However, since we are naming an ester, we replace the 'ic acid' suffix with 'ate', resulting in butanoate.
Thus, the complete systematic name for this ester is ethyl 3-methyl butanoate.
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Provide the systematic name for the following ester.
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propyl butanoate
B
butyl propanoate
C
isopropyl butanoate
D
isobutyl propanoate
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Provide the systematic name for the following ester.
A
tert-butyl 3,3-dimethylpentanoate
B
sec-butyl 3,3-dimethylpentanoate
C
tert-butyl 4,4-dimethylpentanoate
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isopropyl 3,3-dimethylpentanoate
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If the substituent name of benzene is phenyl, which structure represents phenyl propanoate?
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B
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D
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Common Naming: Esters Concept 2
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3mCommon Naming: Esters Concept 2 Video Summary
Esters are organic compounds formed from the reaction of an alcohol and a carboxylic acid, and their naming follows specific conventions. When using common names for esters, the naming structure consists of the substituent, prefix, and modifier, with the parent chain typically ending in "ate." To illustrate this, let’s break down the naming process step by step.
First, identify the alkyl group connected to the oxygen atom of the ester. For example, if there is a three-carbon chain attached to the oxygen, it is referred to as "propyl." This alkyl group is named as a substituent and is placed at the beginning of the ester name without a numerical location, as it is directly attached to the oxygen rather than a carbon atom.
Next, determine the length of the carbon chain that includes the carbonyl group (C=O). The carbonyl carbon is considered carbon number one. For instance, if there are five carbons in the chain, the prefix used is "valer," and since it is an ester, the name will end with "ate," resulting in "valerate."
When naming the ester, if there are additional substituents, assign numbers to indicate their positions on the carbon chain. For example, if there is an isopropyl group attached to carbon number two, it is named "2-isopropyl." When multiple identical substituents are present, use prefixes such as "di" for two, "tri" for three, and "tetra" for four. Importantly, all substituents should be listed in alphabetical order, while the numerical prefixes do not count towards this order.
In the final name, ensure to use commas to separate numbers from numbers and dashes to separate letters from numbers. For example, if the alkyl group is propyl and the main chain is 2-isopropyl valerate, the complete name would be "propyl 2-isopropyl valerate." This structure clearly indicates the connection of the propyl group to the oxygen of the ester and the isopropyl substituent's position on the carbon chain.
By following these conventions, one can accurately name esters using common naming systems, ensuring clarity and consistency in chemical communication.
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Problem
Provide common name for given compound.
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cyclopentyl-4,4-dimethyl valerate
B
cyclopentyl 4,4,4-trimethyl butyrate
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cyclopentyl 4,4-dimethyl valerate
D
cyclopentyl-4,4,4-trimethyl butyrate
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Give a common name for the following compound.
A
tert-butyl benzoic acid
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butyl benzoate
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tert-butyl benzoate
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sec-butyl benzoate
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Draw structure for given name: hexyl 3-chlorobutyrate.
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D
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Here’s what students ask on this topic:
What is the general structure of an ester?
An ester is an organic compound characterized by an alkyl group connected to an oxygen atom, which is also bonded to a carbon chain containing a carbonyl group. The general structure can be represented as RCOOR', where R and R' are alkyl or aryl groups. The carbonyl group (C=O) is bonded to the oxygen atom, which in turn is bonded to another carbon chain or alkyl group. This unique structure gives esters their distinctive properties and naming conventions.
How do you name esters using the IUPAC system?
In the IUPAC system, esters are named by modifying the name of the corresponding carboxylic acid. The suffix 'oic acid' of the carboxylic acid is changed to 'ate.' The alkyl group attached to the oxygen atom is named first, followed by the modified name of the acid. For example, if the ester is derived from acetic acid and has a methyl group attached to the oxygen, it is named methyl acetate. The general format is: [Alkyl group] [acid name with 'ate' ending].
What are the steps to name an ester using common names?
To name an ester using common names, follow these steps: 1) Identify the alkyl group attached to the oxygen atom and name it. 2) Identify the carbon chain with the carbonyl group and name it using common name prefixes, ending with 'ate.' 3) Combine the names, starting with the alkyl group followed by the carbon chain name. For example, for an ester with a propyl group attached to a valerate chain, the name would be propyl valerate. If there are multiple substituents, list them in alphabetical order with appropriate prefixes (di-, tri-, etc.).
How do you handle multiple substituents when naming esters?
When naming esters with multiple substituents, follow these steps: 1) Identify and name each substituent. 2) Assign a number to each substituent based on its position on the carbon chain, starting from the carbonyl carbon as position 1. 3) Use prefixes like di-, tri-, and tetra- to indicate the number of identical substituents. 4) List the substituents in alphabetical order, ignoring the prefixes when alphabetizing. For example, if an ester has two methyl groups on the second carbon of a butanoate chain, it would be named dimethyl butanoate.
Why don't we need to specify the location of the alkyl group attached to the oxygen in esters?
In esters, the alkyl group attached to the oxygen atom does not require a numerical location because it is always directly bonded to the oxygen. Unlike other functional groups that can attach to different positions on a carbon chain, the alkyl group in esters has a fixed position. Therefore, specifying its location is unnecessary, simplifying the naming process. For example, in ethyl acetate, 'ethyl' is understood to be attached to the oxygen without needing further clarification.
