EstersEstersThe smelly compoundsThe smelly compounds

What are Esters?What are Esters?

A group of compounds that are A group of compounds that are responsible for some natural and responsible for some natural and synthetic flavourssynthetic flavours

They are often found in ice-creams, They are often found in ice-creams, lollies, flowers, perfumes and fruits.lollies, flowers, perfumes and fruits.

What are esters?What are esters?

Some contain small molecules.Some contain small molecules. Predict the boiling point and volatility of Predict the boiling point and volatility of

small esters from this information.small esters from this information.

What are esters?What are esters?

Small esters ability to evaporate easily Small esters ability to evaporate easily allows them to reach your nose!allows them to reach your nose!

Larger esters are oils and waxes.Larger esters are oils and waxes.

How are Esters made?How are Esters made?

Condensation reactionCondensation reaction This is between a carboxylic acid and an This is between a carboxylic acid and an

alcoholalcohol It produces an ester and waterIt produces an ester and water

carboxylic acid + alcohol carboxylic acid + alcohol ester + water ester + water

-COOH + -OH -COO + H20

The functional group of an ester is -COOHThe functional group of an ester is -COOH

Condensation Example:Condensation Example:Ethanoic acid + ethanol Ethanoic acid + ethanol ethyl ethanoate + water ethyl ethanoate + water

C2H3OOH + C2H5OH CH3COOCH2CH3 + H2O

The OH from the alcohol and the H from the OH on the carboxylic acid break away to form water.

The affected carbons from the alcohol and the carboxylic acid join together and form the ester

Draw the products of the Draw the products of the following reactionsfollowing reactions

Naming EstersNaming Esters

The name of the esters produced has 2 The name of the esters produced has 2 parts:parts:

1)1) Derived from the name of the alcohol with Derived from the name of the alcohol with -yl replacing –anol-yl replacing –anol

2)2) Derived for the name of the carboxylic acid Derived for the name of the carboxylic acid where –ic acid is replaced with –atewhere –ic acid is replaced with –ate

E.g. ethanol and ethanoic acid react to form E.g. ethanol and ethanoic acid react to form ethyl ethanoate and waterethyl ethanoate and water

Have a go!Have a go!

What is the name of the Ester that would What is the name of the Ester that would be produced from the condensation of be produced from the condensation of methanol and propanoic acid?methanol and propanoic acid?

Methyl propanoate

Have a go!Have a go!

What is the name of the Ester that would What is the name of the Ester that would be produced from the condensation of be produced from the condensation of butanol and heptanoic acid?butanol and heptanoic acid?

Butyl heptanoate

Questions:Questions:

1. Write reactions to show the production of:

Methyl ethanoate

Ethyl propanoate

2. Write the equation for the formation of the following esters:

CH3COOCH2CH3

CH3CH2COOCH2CH3