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The mechanism for base-catalyzed aldol condensation can be seen in the image below. A mechanism for aldol condensation in basic conditions, which occurs via enolate intermediates and E1CB elimination. The process begins when a free hydroxide (strong base) strips the highly acidic proton at the alpha carbon of the aldehyde.
The scheme shows a simple mechanism for the base-catalyzed aldol reaction of an aldehyde with itself. Simple mechanism for base-catalyzed aldol reaction of an aldehyde with itself Although only a catalytic amount of base is required in some cases, the more usual procedure is to use a stoichiometric amount of a strong base such as LDA or NaHMDS .
After which it may undergo dehydration to give a unsaturated carbonyl compound, the aldol condensation product. The scheme shows a simple mechanism for the base-catalyzed aldol reaction of an aldehyde with itself. Base-catalyzed aldol reaction. Simple mechanism for base-catalyzed aldol reaction of an aldehyde with itself. Base-catalyzed dehydration
Idealized scheme showing condensation of two amino acids to give a peptide bond. Many variations of condensation reactions exist. Common examples include the aldol condensation and the Knoevenagel condensation , which both form water as a by-product, as well as the Claisen condensation and the Dieckman condensation (intramolecular Claisen ...
The Hajos–Parrish–Eder–Sauer–Wiechert and Barbas-List [1] reactions in organic chemistry are a family of proline-catalysed asymmetric aldol reactions.. In the 1970s, two research groups discovered (and published) almost simultaneously their discoveries of two related intramolecular reactions: Zoltan Hajos and David Parrish at Hoffmann-La Roche [2] [3] and Rudolf Wiechert et al at ...
In organic chemistry, an aldol is a structure consisting of a hydroxy group (-OH) two carbons away from either an aldehyde or a ketone. The name combines the suffix 'ol' from the alcohol and the prefix depending on the carbonyl group , either 'ald' for an aldehyde, or 'ket' for a ketone, in which case it referred to as a 'ketol'.
Below, the reaction mechanism is shown with R 2 = H: Mukaiyama Aldol-MechanismusV7 en. In the cited example the Lewis acid TiCl 4 is used. First, the Lewis acid activates the aldehyde component followed by carbon-carbon bond formation between the enol silane and the activated aldehyde. With the loss of a chlorosilane the compound 1 is built.
The Baeyer–Drewsen indigo synthesis (1882) is an organic reaction in which indigo is prepared from 2-nitrobenzaldehyde and acetone [1] [2] The reaction was developed by von Baeyer and Viggo Drewsen in 1880 to produce the first synthetic indigo at laboratory scale.