/sup 13/C and /sup 1/H NMR spectra and structure of the products from the condensation of 1,3-dicarbonyl compounds with aldehydes
The structure of the diadducts formed in the reaction of 1,3-dicarbonyl compounds with aldehydes in a ratio of 2:1 under the conditions of the Knoevenagel condensation was studied by /sup 13/C and /sup 1/H NMR spectroscopy. It was shown that acyclic tetracarbonyl compounds are formed in the absence of a catalyst while substituted cyclohexanones are formed in the presence of piperidine. The acyclic tetracarbonyl compounds exist mainly in the tetraketo form in solution, and the presence of the monoenol form was established for dimethyl 2,4-diacetylpentanedioate in CD/sub 2/Cl/sub 2/. The most characteristic signals which distinguish between the cyclic diadducts and the acyclic products are the signals of the C/sup 5/ (delta 72 ppm) and C/sup 6/ (delta 52 ppm) atoms. The presence of a keto-enol equilibrium in 2,4-diacetyl-5-hydroxy-3-(p-methoxyphenyl)-5-methylcyclohexanone was demonstrated by /sup 13/C NMR.
- Research Organization:
- A.A. Zhdanov Leningrad State Univ. (USSR)
- OSTI ID:
- 6089607
- Journal Information:
- J. Org. Chem. USSR (Engl. Transl.); (United States), Journal Name: J. Org. Chem. USSR (Engl. Transl.); (United States) Vol. 23:12; ISSN JOCYA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
ACTIVATION ENERGY
ADDUCTS
ALCOHOLS
ALDEHYDES
AMINES
AZINES
CARBON 13
CARBON ISOTOPES
CATALYSIS
CATALYTIC EFFECTS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CHEMICAL SHIFT
CHLORINATED ALIPHATIC HYDROCARBONS
CHLOROFORM
CYCLOHEXANONE
DEHYDROCYCLIZATION
DEUTERIUM COMPOUNDS
ENERGY
ENOLS
EVEN-ODD NUCLEI
HALOGENATED ALIPHATIC HYDROCARBONS
HETEROCYCLIC COMPOUNDS
HYDROGEN 1
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
ISOTOPE EFFECTS
ISOTOPES
KETONES
LIGHT NUCLEI
LINE WIDTHS
METHYLENE CHLORIDE
MOLECULAR STRUCTURE
NMR SPECTRA
NUCLEI
ODD-EVEN NUCLEI
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PIPERIDINES
PYRIDINES
SPECTRA
STABLE ISOTOPES
STRUCTURAL CHEMICAL ANALYSIS
YIELDS