User:Stone/Benzaldehyde
From Wikipedia, the free encyclopedia
’’’Benzaldehyde’’’ C7H6O, is a colourless liquid and the simplest aromatic aldehyde. The characteristic and pleasant almond-like odor of benzaldehyde makes it an important component as food ingrediant, artifical flavour and as ingredient for perfumes. It is the primary component of bitter almond oil extract, and can be extracted from a number of other natural sources in which it occurs, such as apricot, cherry, and laurel leaves, peach seeds and, in a glycoside combined form (amygdalin), in certain nuts and kernels. Currently benzaldehyde is primarily made from toluene by a number of different processes.
On oxidation, for example if in contact with air, benzaldehyde is converted into benzoic acid. On reduction, benzyl alcohol can be formed, transition metal catalysed hydrogenation or metal hydrides are used for this purpose.
In basic conditions, potassium or sodium hydroxide for example, a reduction and oxidation process (disproportionation) occurs, which result in the production of potassium benzoate and benzyl alcohol. This Cannizzaro's reaction is a common reaction for aromatic aldehydes. The speed of this reaction depends on the substituents present in the aromatic ring. Because of the air oxidation and the Cannizzaro's reaction benzaldehyde always contains small amounts of benzoic acid and benzyl alcohol, which can be separated by fractionated distillation.
[edit] Biology
almonds apricot, apple and cherry kernels, contain significant amounts of (amygdalin). This glycoside breaks um under enzyme catalysis into benzaldehyde hydrocyanic acid and two molecules of glucosis.
