Synthesis of exo- and endocyclic enamino derivatives of 2-(3-arylprop-2-enoyl)cyclohexane-1,3-diones

Abstract

Condensation of 2-acetylcyclohexane-1,3-diones with aromatic aldehydes in the presence of piperidine, pyrrolidine, hexamethyleneimine, or morpholine gave the corresponding 2-(3-arylprop-2-enoyl)cyclohexane-1,3-diones as the major products and 2-[3-aryl-1-cycloalkylaminoprop-2-en-1-ylidene]cyclohexane-1,3-diones as minor ones. Endocyclic enamino derivatives were synthesized in two steps through enol methyl ethers which reacted with amines. Endocyclic enamino derivatives of 2-(3-arylprop-2-enoyl)cyclohexane-1,3-diones containing an aryl group on the nitrogen atom readily underwent cyclization to 1,2,3,4,5,6,7,8-octahydroquinoline-4,5-dione derivatives.

Reaction of Nitromethane with Cinnamoyl Derivatives of Cyclic β-dicarbonyl Compounds. Application to the Synthesis of 2(3)-(4-aryl-pyrrolidin-2-ylidene)-1,3(2,4)-diones*

“…Conversion of endo-cyclic tautomers A, B into the exo-cyclic ones C, D transforms the enone system of the side chain into the diene moiety which makes the Michael reaction at this fragment problematic. As in the case of the precursors 1-5, cyclic β-tricarbonyl system of the compounds 6-10 exists in solution in the enol form (B or D), which is confirmed by their NMR spectra and literature data [17,22,28,34]. However, under the described conditions nitromethane reacted with compounds 6-10 according to the scheme of 1,4-conjugate addition to the enone fragment of cinnamoyl moiety to give nitromethyl derivatives 11-15 in 47-92% yield ( Table 2).…”

“…β-Diketone Cinnamoyl Derivatives 6, 10 were prepared according to the reported method A [22,34]. The residue was acidified with 1 N HCl (15 ml) at 5°C.…”

Computational Study on the Acid Catalyzed Reactions of Fluorine-Containing 2,4-Dialkoxy-3,4-dihydro-2H-pyrans with Aromatic Compounds

“…Similar ring-opening reaction of fluorine-containing dihydro-2H-pyrans giving 6-aryl-1,1,1,5,5,5-hexafluoro-3-[(E)-3-propylidene]pentane-2,4-diones (6) was also found in the reaction of 2-ethoxy-4-isobutoxy-5-trifluoroacetyl-6-trifluoromethyl-3,4-dihydro-2H-pyran (5) [7] with aromatic compounds in refluxing trifluoroacetic acid [8]. Derivatives having the skeletons of dihydropyrans (2), 4H-pyrans (3), and 1,3-butadienes (4 and 6) have a high potential use as synthetic intermediates to access a variety of heterocycles [9][10][11][12][13][14][15]. Hence, highly important practices for the constructions of various kinds of novel fluorine-containing heterocyclic systems would be provided by the above reactions of dihydropyrans, 1 and 5.…”

Citotoxicidade e atividade herbicida de análogos sintéticos de 2-acil-cicloexano-1,3-dionas de espécies de Peperomia

“…e morfolina (1,2 mmol; 0,3 equiv. ), a mistura reacional foi refluxada por 12 horas em um balão de 100 mL equipado com Dean-Stark (Rubinov et al, 2011). A mistura foi então resfriada até temperatura ambiente e particionada com 100 mL de solução 1M HCl e 100 mL de acetato de etila.…”