Synthesis of Ketones - Oxidation of Secondary Alcohols:
Aldehydes and ketones are synthesized by the oxidation of
various kinds of alcohols.
The definitions which are used in inorganic chemistry involving
the gain or loss of electrons; or the increase or decrease in
oxidation numbers are not very useful in organic chemistry. In
organic chemistry, although changes in electrons are important,
oxidation and reduction is more readily observed from changes
in the number of hydrogen or oxygen atoms. The definitions are
OXIDATION: loss of hydrogen, gain in oxygen, or loss
REDUCTION: gain of hydrogen, loss of oxygen, or gain
The oxidation of secondary alcohols yields ketones. In the
oxidation of an alcohol, the oxidizing agent, usually represented
by (0), removes the hydrogen and electrons from the alcohol,
the reducing agent. The "0" in the oxidizing agent
is some unspecified oxygen atom which reacts with the hydrogen
atoms to form water.
The oxidation of a secondary alcohol leads to the formation
of ketones. This relationship should be clear if you carefully
consider the position of the -OH group in a secondary alcohol
and the position of the carbonyl group in a ketone. Both functional
groups are not on a terminal carbon. On the other hand, a primary
alcohol and the aldehyde are on the terminal carbon.