This chapter contains oxygen compounds in which oxygen is bonded to a carbon atom through a double bond. The functional unit >C = O, present in these compounds is called carbonyl group. We limit our study now to compounds having an acyl group (R - C = O) is bonded to hydrogen, carbon, oxygen, halogens and nitrogen. These compounds are known as carbonyl compounds and are grouped into families of aldehydes, ketones, carboxylic acids and their derivatives.
Aldehydes are considered to be derivatives of hydrocarbons in which two hydrogen atoms attached to a carbon atom at the end of the chain have been replaced by a bivalent oxygen.
Aldehydes are the compounds having the
general formula
where R is H, alkyl group or an aryl group. Aldehydes are
characterisied by the presence of a functional group
called aldehyde group.
Ketones are class of compounds characterized by the presence of a carbonyl group >C = O united to two alkyl groups. They are called simple ketones or mixed ketones depending a whether the two alkyl groups attached to the ketonic group are same or different.
Ketones are derivatives of alkanes obtained by the replacement of two hydrogen atoms attached to a carbon atom in the middle of the chain by an oxygen atom.
Ketones have a formula
where R and R' are the alkyl or aryl groups.
Ketones are characterized by a functional group >C = O called the ketonic group.
Aldehydes and ketones are the simplest but most important carbonyl compounds.
