By: Adrianne Nelson

ESTERS

What are Esters? They are an organic compound made by replacing

the hydrogen of an acid by an alkyl or other organic group.

Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries.

What are esters (continued…)

Esters comprise most naturally occurring fats and oils. 

An important case are glycerides, which are fatty acid esters of glycerol.

Esters with low molecular weight are commonly used as fragrances and found in essential oils and pheromones.

Characteristics Esters are more polar than ethers but

less polar than alcohols They participate in hydrogen bonds as

hydrogen-bond acceptors, but cannot act as hydrogen-bond donors

Esters are more volatile than carboxylic acids of similar molecular weight

Carboxylic acid esters are commonly prepared by reaction of carboxylic acids and alcohols in the presence of hydrochloric acid or sulfuric acid, a process called esterification.

In the reaction the hydroxyl group (OH) of the carboxylic acid is replaced by the alkoxy group (R′O) of the alcohol.

General name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product.

Esterification

What are they used for? Esters are used for their distinctive odors and are

commonly used for food aroma and fragrances They are mostly used for artificial fruit flavoring

http://www.youtube.com/watch?v=ecHKrd7hn4U&edufilter=FwNIMIqIDIQYAexPZDE7XA

Most commonly used ester is ethyl ethanoate.

The hydrogen in the -COOH group has been replaced by an ethyl group.

This colorless liquid has a characteristic sweet smell and is used in glues, nail polish removers, decaffeinating tea, coffee, and cigarettes

Ethyl ethanoate

Carbonate esters A  carbonate ester is an ester

of carbonic acid. This functional group consists of

a carbonyl group flanked by two alkoxy groups.

Carbonate esters are used for organic synthesis, used as solvents, and are used in batteries

http://goanimate.com/yourvideos

Quiz1. What are Esters used for?

a. food flavoringb. cancer drugsc. pain relief

2.What is the most commonly used Ester?a. Ethyl formate b. Ethyl ethanoatec. Ethyl propanoate

3. What is Ethyl ethanoate NOT used in?a. coffeeb. nail polish removerc. perfume

4. Esters are:a. nonpolarb. polarc. neither

5. Carbonate esters are NOT used for: a. organic synthesis

b. used as solventsc. fruit odors

http://www.britannica.com/EBchecked/topic/193393/ester

Works Cited

http://www.ivyroses.com/Chemistry/Organic/Naming-Esters.php http://wiki.chemprime.chemeddl.org/index.php/Esters_in_Foods