Calcium stannyl formation by organostannane dehydrogenation

Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.

Regular Claisen condensation involves the synthesis of β-ketoesters by combining identical ester molecules bearing two α hydrogens in the presence of an alkoxide base. The reaction commences with the deprotonation of the acidic α hydrogen by the base to form a resonance stabilized ester enolate. This nucleophilic ion then attacks the carbonyl center of another ester molecule to generate a tetrahedral alkoxide intermediate. Next, the expulsion of the alkoxide group from the...

The Knoevenagel condensation is an aldol-type reaction involving the condensation of aldehydes or ketones with active methylene compounds such as β-diesters to produce substituted olefins.

α-Substituted ketones or aldehydes can be synthesized from enamines by the Stork enamine reaction, named after its pioneer Gilbert Stork. Enamines are useful synthetic intermediates where the lone pair on nitrogen is in conjugation with the C=C bond. They resemble enolate ions, as the resonance forms of both species have a nucleophilic α carbon.

Crossed Claisen condensations are base-promoted reactions between two different ester molecules producing β-dicarbonyl compounds.  The reaction involving esters, with both containing α hydrogen, results in a mixture of four different products that are difficult to isolate. This reduces the synthetic utility of the reaction.

Esters are reduced to primary alcohols when treated with a strong reducing agent like lithium aluminum hydride. The reaction requires two equivalents of the reducing agent and proceeds via an aldehyde intermediate.
Lithium aluminum hydride is a source of hydride ions and functions as a nucleophile. The mechanism proceeds in three steps. Firstly, the nucleophilic hydride ion attacks the carbonyl carbon of the ester to form a tetrahedral intermediate. Subsequently, the carbonyl group re-forms,...