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Biological Chemistry FIRST YEAR ORGANIC CHEMISTRY. Lecture Eight Carboxylic acids + Esters. Convenor : Dr. Fawaz Aldabbagh. Carboxylic Acids. We can distinguish a water-insoluble carboxylic acid and phenol from an alcohol. Carboxylic Acids. Highly Polar
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Biological ChemistryFIRST YEAR ORGANIC CHEMISTRY Lecture Eight Carboxylic acids + Esters Convenor: Dr. Fawaz Aldabbagh
Carboxylic Acids We can distinguish a water-insoluble carboxylic acid and phenol from an alcohol
Carboxylic Acids Highly Polar Low molecular weight acids show Appreciable Solubility in Water High Bpt – Extensive H-bonds to themselves and water NAMES Ethanoic acid Methanoic acid Propanoic acid Red ants rhubarb 4-Bromo-2-ethylpentanoic acid Ethanedioic acid (oxalic acid) Terephthalic acid Phthalic acid
Esterification Alcohol part appears first in the name
Equilibrium reaction • Reversible with acid • And water Ester molecules cannot H-bond to each other, because they do not have an –OH Consequently, B.pt is much lower than that of alcohols and acids of comparable mass H-bonding to water is possible -low mw esters are soluble in water Solubility rapidly decreases with carbon chain length.
Esters are also largely responsible for the flavour and smell of fruits and flowers Salicyclic acid is the active ingredient of aspirin. - It has analgesic, antipyretic and anti-inflammatory properties Buffered aspirin contains bases. Esters are hydrolysed in acid and base catalysed reactions
Ester Saponification - is the base-catalysed hydrolysis of an ester
Write a mechanism for the acid and base hydrolysis of a lactone
Redox Reactions Addition of Oxygen or Removal of Hydrogen is OXIDATION Removal of Oxygen or Addition of Hydrogen is REDUCTION
Examples of Reduction Reactions Examples of Oxidation Reactions