Post on 10-Jan-2016
description
Esters and Esterification
• Write condensed structural formulas for and name esters.
Include: uses and functions of common esters
Additional KEY Termsesterification
The functional group of esters is the ester group
• general formula: R–COOR'R - hydrocarbon chain from the acid R' - hydrocarbon chain from the alcohol.
O
O CR O
carbonyl group
alkoxy group
R'
• made by combining carboxylic acid and alcohol
alcoholcarboxyl acid
H
C-C
O
O H O-C
ester
waterEsterification is a reversible reaction.
DE-esterification
Esterification
Properties of Esters:
• Polar covalent: < 5C (small) are soluble in water
O
O CR O
δ+δ-
• Large esters account for flavour / odor of fruit
• Strong IMF (d-d) gives high bp/mpBut lower than alcohol/acids – NO H-bonding
R'
Ester Odorisoamyl acetate bananamethyl salicylate wintergreenethyl butyrate pineapplebenzyl butyrate cherrybenzyl acetate peachmethyl butyrate appleoctyl acetate orangen-propyl acetate pearethyl phenylacetate honeyethyl acetate fingernail polish remover
· First name alcohol: change - anol to - yl· Second name acid: change - ioc acid to - oate
Naming Esters2 – 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.
CAN YOU / HAVE YOU?
• Write condensed structural formulas for and name esters.
Include: uses and functions of common esters
Additional KEY Termsesterification