The Kowalski ester homologation is a chemical reaction

Chemical reaction

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...

 for the homologation

Homologation reaction

A homologation reaction, also known as homologization, is any chemical reaction that converts the reactant into the next member of the homologous series. A Homologous series is a group of compounds that differ by a constant unit, generally a group. The reactants undergo a homologation when the...

 of ester

Ester

Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

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This reaction was designed as a safer alternative to the Arndt-Eistert synthesis

Arndt-Eistert synthesis

The Arndt-Eistert synthesis is a series of chemical reactions designed to convert a carboxylic acid to a higher carboxylic acid homologue and is considered a homologation process...

. The Kowalski reaction is named after its inventor, Conrad J. Kowalski.

Reaction mechanism

The mechanism is disputed.

Variations

A modification of the procedure has been described that results in higher yields.

By changing the reagent

Reagent

A reagent is a "substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs." Although the terms reactant and reagent are often used interchangeably, a reactant is less specifically a "substance that is consumed in the course of...

 in the second step of the reaction, the Kowalski ester homologation can also be used for the preparation of silyl ynol

Ynol

In chemistry, an ynol is an alkyne with a hydroxyl group affixed to one of the two carbons composing the triple bond. The deprotonated anions of ynols are known as ynolates...

 ether

Ether

Ethers are a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...

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