Aldol condensation In the aldol condensation the α-carbon of one aldehyde or ketone molecule adds to the carbonyl carbon of another. The base is most often used is -OH. The product is a β-hydroxy aldehyde or ketone, which in some cases is dehydrated during the course of the reaction. Even if the dehydration is not spontaneous, it can usually be done easily, since the new double bond will be in conjugation with the C=O bond. Ritter Reaction Alcohols is converted by a strong acid to a carbocation, which adds to the negative nitrogen. The immediate product tautomerizes to the N-alkyl amide. Only alcohols that give rise to fairly stable carbocation react; primary alcohols do not give the reaction. The carbocation need not be generated from an …show more content…
This method is only useful phenols and certain heterocyclic compounds such as pyrroles and indoles. This reaction is conducted in basic solution. Yields are generally low, seldom rising above 50%. Haller-Bauer reaction This reaction is known for the cleavage of ketones with sodium amide. The reaction is usually applied only to nonenolizable ketones, most often to ketones of the form ArCOCR3, where the products R3CCONH2 are not easily attainable by other methods. However, many other ketones have been used, though benzophenone is virtually unaffected. It has been shown that the configuration of optically active R is retained. The NH3 loses its proton before the R is cleaved. Perkin Reaction The condensation of aromatic aldehydes with anhydrides is called the perkin reaction. When the anhydride has two α-hydrogens, dehydration always occurs; the β-hydroxy acid salt is never isolated. In some cases, anhydrides of the form (R2CHCO)2O have been used, and then the hydroxyl compound is the product since dehydration cannot take place. This base in the reaction is nearly always the sodium or potassium salt of the acid corresponding to the