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Chapter 16 Carboxylic Acids and Esters

16.3 Esters16.4 Naming Esters

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Esters

In an ester, the H in the carboxyl group is replaced with an alkyl group

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Esterification is the reaction of a carboxylic acid and alcohol in the

presence of an acid catalyst to produce an ester

Esterification

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Write the equation for the reaction of propanoic acid and methanol in the presence of an acid catalyst.

Learning Check

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Write the equation for the reaction of propanoic acidand methanol in the presence of an acid catalyst.

Solution

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Ester Products

Aspirin is used to relieve pain and

reduce inflammation is an ester of salicylic acid

and acetic acid

Oil of wintergreen is used to soothe sore

muscles is an ester of salicylic acid

and methanol

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Esters in Plants

Esters give flowers and fruits theirpleasant fragrances and flavors.

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Guide to Naming Esters

8

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Naming Esters

The name of an ester contains the names of the alkyl group from the alcohol the carbon chain from the acid with -ate ending

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Learning Check

Give the IUPAC and common names of the following compound, which is responsible for the flavor and odor of pears:

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from 1-propanol

STEP 1 Write the carbon chain from the alcohol as alkyl. Propyl

STEP 2 Change ic acid to ate. Ethanoate (acetate) Propyl ethanoate (IUPAC name)

Propyl acetate (common name)

Solution

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Learning Check

Name the following esters:

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Solution

A. STEP 1 Write the carbon chain from the alcohol as alkyl. Methyl

STEP 2 Change butanoic acid (butyric acid) to butanoate (butyrate).Methyl butanoate (methyl butyrate)

B. STEP 1 Write the carbon chain from the alcohol as alkyl. Ethyl

STEP 2 Change propanoic acid (propionic acid) to propanoate (propionate)Ethyl propanoate (ethyl propionate)

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Learning Check

Draw the condensed structural formula of the followingesters: A. Ethyl pentanoate

B. Propyl butyrate

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Solution Draw the condensed structural formula of the followingesters:

A. Ethyl pentanoate B. Propyl butyrate