Key Concepts In Organic Chemistry: Carboxylic Acids
-The carboxylic acid functional group results from the connection of a carbonyl functional group to a
hydroxyl group. This implies the fact that carboxylic acids will do hydroxyl reactions, carbonyl group
reactions and the OH can function as a good LG if protonated. In IUPAC nomenclature, the COOH is
always given priority, the C of the COOH is #1, and the –e in the word “alkane” is changed to –oic acid.
The very simple acids are known by their common names (formic acid, acetic acid and oxalic acid). If a
molecule contains a C = 0 in addition to an acyl group, its position is noted by the prefix oxo.
-In carboxylic acids, the polar bonds are located at one end of the molecule, termed the hydrophilic end,
which strongly interacts with water. The other end of the molecule with the R group, termed the
hydrophobic end, is non-polar and has very low solubility in water.
-The IR spectrum of carboxylic acids contains two strong, characteristic peaks: a C = O peak at 1700-
1752cm and a very broad OH peak at 2400-3400cm . In proton NMR, the acidic H of the carboxylic acid
group appears far downfield (to the left) at δ = 10-13.
-On exposure to bases, carboxylic acids react to form water-soluble salts (they are strong, organic weak
acids). Carboxylic acids are easily prepared by the oxidation of 1° alcohols and aldehydes (except when
PCC is used as the oxidizing agent).
-In the reduction to 1° alcohols reaction, other reducing agents that hydrogenate alkenes and carbonyl
groups (such as NaBH ) 4re used which do not affect carboxylic acid groups.
-Carboxylic acids th