Aldehyde
An aldehyde is an organic compound containing a carbonyl group (C=O) bonded to at least one hydrogen atom and one other atom, which can be hydrogen or a carbon atom. The general formula for an aldehyde is RCHO, where R represents the side chain. The carbon atom of the carbonyl group is sp2-hybridized and forms sigma bonds to the hydrogen and R group, as well as a pi bond to the oxygen atom. This arrangement results in a trigonal planar geometry around the carbonyl carbon.
Aldehydes are named according to IUPAC nomenclature by replacing the "-e" ending of the corresponding alkane name with "-al." For example, methanal (formaldehyde) is derived from methane, and ethanal (acetaldehyde) is derived from ethane. If the aldehyde group is attached to a cyclic structure, the suffix "-carbaldehyde" is used.
Aldehydes are generally more reactive than ketones due to the presence of the hydrogen atom directly bonded to the carbonyl carbon. This makes them more susceptible to oxidation. Common reactions of aldehydes include oxidation to carboxylic acids, reduction to alcohols, and nucleophilic addition reactions at the carbonyl carbon.
Aldehydes are found in a wide variety of natural products and are also important industrial chemicals. They can be produced through various methods, including oxidation of primary alcohols, ozonolysis of alkenes, and reduction of acyl chlorides. Specific aldehydes, such as formaldehyde, are used in the production of resins, plastics, and other materials. Others contribute to flavors and fragrances.