Synthesis of a Triglyceride:
Since glycerol, (IUPAC name is 1,2,3-propantriol), has three
alcohol functional groups, three fatty acids must react to make
three ester functional groups. The three fatty acids may or may
not be identical. In fact, three different fatty acids may be
The synthesis of a triglyceride is another application of
the ester synthesis reaction. To write the structure of the triglyceride
you must know the structure of glycerol and be given or look
up the structure of the fatty acid
in the table - find lauric acid.
The simplified reaction reveals the process of breaking some
bonds and forming the ester and the by product, water. Refer
to the graphic on the left for the synthesis of trilauroylglycerol.
First, the -OH (red) bond on the acid is broken and the -H (red)
bond on the alcohol is also broken. Both join to make HOH, a
Secondly, the oxygen of the alcohol forms a bond (green) to
the acid at the carbon with the double bond oxygen. This forms
the ester functional group. This process is carried out three
times to make three ester groups and three water molecules.
QUES. Practice writing out a triglyceride of stearic acid.
Again look up the formula of stearic
acid and use the structure of glycerol.