Aldehydes

Aldehydes are a class of organic compounds which contain a formyl group, represented by -C(=O)H. Most of the aldehydes are colorless or pale-colored liquids with noticeable odors. The aldehydes, containing alpha-hydrogen, can exist as either a keto or enol tautomer, in which the enol tautomer is more reactive. Aldehydes generally undergo addition reactions, by losing a water molecule and therefore it is known as an addition-elimination or condensation reaction. Cyanohydrins, formed through this mechanism, are a route to the synthesis of important alpha-hydroxy acids. Aldehydes are efficient partners in the Witting reaction for the synthesis of olefins. They are also important intermediates in organic synthesis for the preparation of alcohols, imines and amines.

Aldehydes are important industrial compounds and are mainly used as solvents. Aromatic aldehydes are extensively employed in medicinal chemistry for the preparation of a large array of diverse molecules. They are used in intermediate steps for the production of paints, plastics, synthetic resins, and dyes. They are also used in the manufacture of perfumes, solvents, and flavorings.