ALDOLS

ALDOLS, ^-oxyaldehydes, organic compounds that combine in their molecule both aldehyde and alcohol functions. Aldols are obtained by the condensation of aldehydes in the presence of zinc chloride or potash. The process of formation of aldols is called aldol condensation and proceeds in such a way that from two molecules of aldehyde (identical or different) one molecule of aldol is formed: R.CH:O + H.CH.CH:O = !! R = R.CHfOH>.CH.CH: O. and li R Of these compounds, the ordinary aldol, CH₃.CH(OH).CH₂.CHO, is best known, which readily gives up a particle of water upon heating to form crotonic aldehyde, CH₃.CH=CH.CH:O. This property is common to all aldols, and therefore in organic synthesis they are used to obtain unsaturated aldehydes. Aldol condensation apparently plays a role in intermediate exchange processes, through which a transition can occur from simpler to higher molecular compounds, in particular, from carbohydrate-derived compounds (acetaldehyde) to higher fatty acids, as well as an intermediate product in fermentations. In the animal organism, aldols may serve as a source for the formation of beta-oxymethyl acid.