Reactions of Aldehydes & Ketones
Oxidation of Aldehydes
aldehydes can be oxidized to carboxylic acids by
chromic acid
Tollen’s Reagent is made of silver ion, ammonia, and hydroxide ion
this reaction can also be called the silver mirror test or Tollen’s test
Example with Chromic Acid
Example with Tollen’s Reagent
Formation of Hemiacetals & Acetals with Alcohols
Formation of Hemiacetals
aldehydes/ketones and hemiacetals exist in equilibrium when dissolved in an alcohol
the reaction to form a hemiacetal is an example of an addition reaction
Formation of Acetals
aldehydes/ketones can be formed into acetals in the presence of
an acid catalyst
excess of alcohol
this reaction results in the loss of a water molecule
the aldehyde/ketone actually reacts with 2 molecules of the alcohol
Hydrolysis of Acetals
Hydrolysis reaction: a reaction where water breaks the bonds in a compound
The hydrolysis of an acetal is the reverse reaction of acetal formation
This is a reversible reaction and is controlled by the amounts of reactants used
Reduction of Aldehydes to Alcohols
This reaction can be done using one of two agents
Sodium borohydride
Lithium aluminum hydride (LAH)
also reduces carboxylic acids, esters, and amides
Reactions of Aldehydes & Ketones
Oxidation of Aldehydes
aldehydes can be oxidized to carboxylic acids by
chromic acid
Tollen’s Reagent is made of silver ion, ammonia, and hydroxide ion
this reaction can also be called the silver mirror test or Tollen’s test
Example with Chromic Acid
Example with Tollen’s Reagent
Formation of Hemiacetals & Acetals with Alcohols
Formation of Hemiacetals
aldehydes/ketones and hemiacetals exist in equilibrium when dissolved in an alcohol
the reaction to form a hemiacetal is an example of an addition reaction
Formation of Acetals
aldehydes/ketones can be formed into acetals in the presence of
an acid catalyst
excess of alcohol
this reaction results in the loss of a water molecule
the aldehyde/ketone actually reacts with 2 molecules of the alcohol
Hydrolysis of Acetals
Hydrolysis reaction: a reaction where water breaks the bonds in a compound
The hydrolysis of an acetal is the reverse reaction of acetal formation
This is a reversible reaction and is controlled by the amounts of reactants used
Reduction of Aldehydes to Alcohols
This reaction can be done using one of two agents
Sodium borohydride
Lithium aluminum hydride (LAH)
also reduces carboxylic acids, esters, and amides