Aldehyde and ketone are very commonly known as organic compounds which further incorporate a carbonyl functional group. In very much of scientific language the carbon atom of this group has two bonds remaining which may be occupied by hydrogen or alkyl, aryl substituents. One of this substituent which has at least one hydrogen is known as aldehyde. The another subsistent which contains nitrogen is known as ketone.An aldehyde carbonyl group must lie at the end of the carbon chain with which it becomes by default number one and hence defines the numbering directions. A ketone carbonyl can be located anywhere within the chain or the ring as the position is given by a locator. The numbering of the chains starts from the nearest carbonyl group. In another form which is called as cyclic form where the ketones are assigned number one position in carbonyl group. Simple and types of ketones such as propane and phenylethanone generally do not require locator number as there is only one possible site for ketone carbonyl function. In this the other functional groups are treated as substituent as because ketones are placed right below aldehyde in nomenclature suffix priority the terminology used is substituent where seldom is very much needed.
There are various stages involved which include occurrence, properties and preparation. These aldehyde and ketones are very much widespread in nature and are combined with other functional group as these compounds in the top row are found chiefly in plants or microorganisms and the bottom row have animal origins and also these are obtained from many reactions as both require double bond functional group. These aldehyde and ketone are considered to be oxygen analogs of alkenes by comparing the structures of formaldehyde with ethane as well s that with the structure of the acetone. The process of reduction also takes place for these aldehyde and ketone.