Chemical Sciences: A Manual for CSIR-UGC National Eligibility Test for Lectureship and JRF/Named Reactions/Stork Enamine Reaction
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Stork enamine alkylation, also known as the Stork-Enamine reaction, involves the addition of an enamine to an alpha, beta-unsaturated carbonyl acceptor in a process similar to the Michael reaction [1]. The product is then hydrolyzed by an aqueous acid to produce a 1,5-dicarbonyl compound.
The process:
- formation of an enamine from a ketone
- addition of the enamine to and alpha, beta-unsaturated aldehyde or ketone
- hydrolysis of the enamine back to a ketone
When the electrophile is an acyl halide, a 1,3-diketone is formed (Stork acylation). The reaction is named after its inventor: Gilbert Stork.
Variations edit
In a special case of this reaction type it is also possible to alkylate ketones or aldehydes with alkyl halides as less reactive electrophiles [2]:
In this method a carbonyl compound is converted to an imine by alkylimino-de-oxo-bisubstitution with a primary amine. The imine is then reacted with an Grignard reagent to the corresponding magnesium salt to an intermediate capable of displacing a halide. Hydrolysis once again yields the alkylated ketone.
References edit
- ↑ McMurry, John (2003-03-21). Organic Chemistry (Hardcover) (6th ed.). Belmont, CA: Thomson-Brooks/Cole. ISBN 0-534-38999-6.
{{cite book}}:|format=requires|url=(help) - ↑ A New Method for the Alkylation of Ketones and Aldehydes: the C-Alkylation of the Magnesium Salts of N-Substituted Imines Gilbert Stork and Susan R. Dowd J. Am. Chem. Soc.; 1963; 85(14) pp 2178 - 2180; doi:10.1021/ja00897a040