Esters The smelly compounds

What are Esters?  A group of compounds that are responsible for some natural and synthetic flavours  They are often found in ice-creams, lollies, flowers, perfumes and fruits.

What are esters?  Some contain small molecules.  Predict the boiling point and volatility of small esters from this information.

What are esters?  Small esters ability to evaporate easily allows them to reach your nose!  Larger esters are oils and waxes.

How are Esters made?  Condensation reaction  This is between a carboxylic acid and an alcohol  It produces an ester and water

carboxylic acid + alcohol  ester + water -COOH + -OH  -COO + H 2 0 The functional group of an ester is -COOH

Condensation Example: Ethanoic acid + ethanol  ethyl ethanoate + water C 2 H 3 OOH + C 2 H 5 OH  CH 3 COOCH 2 CH 3 + H 2 O 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 following reactions

Naming Esters  The name of the esters produced has 2 parts: 1)Derived from the name of the alcohol with -yl replacing –anol 2)Derived for the name of the carboxylic acid where –ic acid is replaced with –ate E.g. ethanol and ethanoic acid react to form ethyl ethanoate and water

Have a go! What is the name of the Ester that would be produced from the condensation of methanol and propanoic acid? Methyl propanoate

Have a go! What is the name of the Ester that would be produced from the condensation of butanol and heptanoic acid? Butyl heptanoate

Questions: 1. 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