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 featuring a carbonyl group adjacent to an oxygen atom bonded to an alkyl group. Their nomenclature modifies the carboxylic acid suffix from "-oic acid" to "-oate" or "-ate" in common names. The alkyl group attached to oxygen is named first without numerical locants, followed by the carbonyl-containing chain named as a substituent with locants for any additional groups. For example, "propyl 2-isopropylvalerate" indicates a propyl group on oxygen and an isopropyl substituent on the second carbon of the valerate chain. This systematic approach aids in identifying esters' structure and functional groups efficiently.
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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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Problem
Provide the systematic name for the following ester.
A
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
D
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
C
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
B
butyl benzoate
C
tert-butyl benzoate
D
sec-butyl benzoate
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Draw structure for given name: hexyl 3-chlorobutyrate.
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D
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In the IUPAC naming system for esters, the carbon chain containing the carbonyl group is named as if it were a carboxylic acid, but the suffix replaces the usual ending. The alkyl group attached to the oxygen atom is named as a substituent and placed at the beginning of the name without a numerical location because it is directly connected to the oxygen, not the carbon chain. The carbonyl carbon is considered carbon number one when numbering the chain. Substituents on the carbon chain are named in alphabetical order with their positions indicated by numbers, and prefixes like di-, tri-, and tetra- are used for multiple identical substituents. Commas separate numbers, dashes separate letters from numbers, and spaces separate the alkyl group name from the rest of the ester name.
Common naming of esters uses common name prefixes for the carbon chain with an ending, while IUPAC naming modifies the carboxylic acid name by replacing with . In both systems, the alkyl group attached to the oxygen is named first as a substituent without a numerical location. The main difference lies in the prefix for the carbon chain: common names use traditional alkyl names (e.g., valerate for a five-carbon chain), whereas IUPAC uses systematic names based on the longest carbon chain containing the carbonyl group. Both systems number substituents on the carbon chain starting from the carbonyl carbon and follow similar rules for indicating substituent positions and multiplicity.
The alkyl group attached to the oxygen atom in esters is named without a numerical location because it is directly bonded to the oxygen, not to any carbon atom in the main carbonyl-containing chain. Since the oxygen atom is the point of attachment, there is no need to specify a position number for the alkyl substituent. This simplifies the naming process and clearly distinguishes the alkyl group connected to the oxygen from substituents on the carbon chain, which do require numbering to indicate their positions.
When naming esters, the parent chain is the carbon chain that contains the carbonyl group. Numbering starts at the carbonyl carbon, which is assigned as carbon number one. This chain is named as if it were a carboxylic acid, but the suffix is changed to to indicate the ester functional group. Substituents attached to this chain are numbered according to their position relative to the carbonyl carbon. The alkyl group attached to the oxygen is named separately as a substituent at the beginning of the ester name.
Substituents on the carbon chain of esters are named by first identifying their position on the chain, with numbering starting at the carbonyl carbon as carbon number one. When multiple identical substituents are present, prefixes such as di-, tri-, and tetra- are used to indicate their quantity. Substituents are listed in alphabetical order, and the prefixes for quantity do not affect this order. Numbers indicating substituent positions are separated by commas, and dashes separate numbers from letters. This systematic approach ensures clarity and consistency in ester nomenclature.
