35244-45-2

Upstream product

• 110-89-4 piperidine 
• 1655-07-8 ethyl 2-oxocyclohexane carboxylate 

Downstream Products

• 99423-45-7 ethyl-3-phenylselenenyl-2-oxo-cyclohexanecarboxylate 
• 1192-88-7 1-cyclohexene-1-carboxaldehyde 
• 30132-23-1 ethyl 3-bromo-2-oxocyclohexanecarboxylate 
• 99423-47-9 ethyl-3-(3-oxo-propyl)-2-oxo-cyclohexanecarboxylate 

Relevant academic research and scientific papers

The γ-alkylation of cyclic β-ketoesters via their enamine derivatives

The γ-alkylation - functionalization of cyclic β-ketoesters via their enamine derivatives is discussed with particular emphasis on their preparation from β-ketoesters and their reaction with various electrophiles such as electrophilic olefins, halogenoids, anmd allylic and benzylic halides.Although the amine ring size does not appear to affect reactivity to a great extent, the reaction is very sensitive to β-ketoester ring size, with six-membered rings giving the best results.In the latter case the alkylation-functionalization is general and specific to the γ-position and therefore provides an important complement to the dianion and related methodologies.

ENAMINE CHEMISTRY-XXV REDUCTION OF ENAMINONONES BY LiAlH4 AND NaBH4 SYNTHESIS OF α,β-UNSATURATED ALDEHYDES

Cyclohexanone, 2-methyl-cyclohexanone and 4-methyl-cyclohexanone, 1, were transformed into the enaminones 4a-4e by the following two routes: (A): Acylation of the enamines, 2, derived from 1 and secondary amines (pyrrolidine, morpholine and piperidine) by ethyl chloroformate, and (B): Condensation of 1 with diethyl oxalate, giving the β-ketoesters 3, followed by reaction with the secondary amines.Ethyl 2(-1-pyrrolidinyl)-1-cyclopentene-1-carboxylate. 4f, and methyl 3-(1-pyrrolidinyl)-2-buteonate, 4g, were prepared from ethyl 2-oxo-1-cyclopentanecarboxylate and ethyl 3-oxo-butanoate, respectively, by condensation with pyrrolidine.Reduction of 4a by LAH afforded 1-cyclohexen-1-carboxaldehyde, 5a, 1-cyclohexene-1-methanol, 6a, and 1-(1-cyclohexene-1-methyl)pyrrolidine, 7a, in yields depending on the molar ratio of LAH/4a.Reduction of 4f by LAH gave cyclopenten-1-methanol, 6b, 1-(1-cyclopentene-1-methyl)pyrrolidine, 7b, and ethyl-2(1-pyrrolidinyl)-1-cyclopentanecarboxylate, 8b.Compound 4g, when reduced with LAH, yielded methyl 3-(1-pyrrolidinyl) butanoate, 8c (main product) and 1-(2-butenyl)pyrrolidine, 7c (minor).Reduction of 4 by NaBH4 afforded exlusively the saturated β-aminoesters, 8, in high yields.The reductions with LAH and NaBH4 are rationalized in terms of the HSAB principle.