Esters and Esterification. Esters produced by combining carboxylic acid and alcohol (esterification)...

Post on 29-Jan-2016

221 views 5 download

Transcript of Esters and Esterification. Esters produced by combining carboxylic acid and alcohol (esterification)...

Esters and Esterification

Esters produced by combining carboxylic acid andalcohol (esterification)

Large chain esters account for flavor and odor of fruits.

General formula: R–COOR'

R - hydrocarbon chain from the acid R' - hydrocarbon chain from the alcohol.

alcoholcarboxyl acid

H

C-C

O

O H O-C

ester

water

Esterification is a reversible reaction.

De-esterification reaction

esterification reaction

H

O

H

O-CC-C

O

+

ester

alcohol

carboxyl acid

H

C-C

O

O H

O-C

· First name alcohol: change "anol" to "yl"· Second name acid: change "ioc acid" to "oate"

Naming Esters

2 – names:

CH3COOCH2CH2CH3

propyl ethanoate

CH3-C

O

\O-CH2CH2CH3

//alcohol

acid

CH3CH2CH2CO + OCH3

butanoic acid methanol

CH3CH2CH2COOCH3 + H2O

methyl butanoate water

OH H

CH3CH2CH2CH2CH2COOCH2CH2CH2CH3

butyl hexanoate

Write the esterification reaction for the reactionbetween pentanoic acid and 1-butanol.

Esters are polar molecules but have NO hydrogen bonding (unlike alcohols, carboxylic acids, water)

Bp / mp are higher than aliphatics but lower than acids and alcohols.

Esters are soluble in water.

• Esterification carboxylic acid and an alcohol thatproduces an ester and water.

• General formula RCOOR' ( R acid, R' alcohol).

• Name is two words: the alkyl group from alcohol,then acid with replaced ending - oate.

• Polar but do not hydrogen bond. Lower melting points and boiling points than acids and alcohols.

• Soluble in water.

Hydroxide ions also catalyze the breakdown ofesters.

salt