- Stork enamine alkylation
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 theMichael reaction [cite book | last =McMurry | first =John | authorlink = John E. McMurry | title =Organic Chemistry | format =Hardcover | edition =6th edition | date =2003-03-21 | publisher =Thomson-Brooks/Cole | location =Belmont, CA | id =ISBN 0-534-38999-6 ] . The product is then hydrolyzed by anaqueous 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-unsaturatedaldehyde or ketone
# hydrolysis of the enamine back to a ketoneWhen the electrophile is an
acyl halide , a 1,2-diketone is formed (Stork acylation) [JerryMarch] . The reaction is named after its inventor:Gilbert Stork .Variations
In a special case of this reaction type it is also possible to alkylate
ketone s oraldehyde s withalkyl halide s as less reactiveelectrophile s ["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. DowdJ. Am. Chem. Soc. ; 1963; 85(14) pp 2178 - 2180; DOI|10.1021/ja00897a040] :In this method a carbonyl compound is converted to an
imine byalkylimino-de-oxo-bisubstitution with a primaryamine . The imine is then reacted with anGrignard reagent to the corresponding magnesium salt to an intermediate capable of displacing a halide.Hydrolysis once again yields the alkylated ketone.References
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