Tautomerism and stereodynamics of acyclic. beta. -diketo esters
The tautomeric transformations and stereodynamics of a series of ring-substituted acyclic ..beta..-diketo esters p-XC/sub 6/H/sub 4/COCH(CH/sub 3/CO)CO/sub 2/CH/sub 3/ in hexachlorobutadiene and nitrobenzene were investigated by proton and carbon magnetic resonance spectroscopy. The enolization of the compounds is accompanied by the formation of two cis-enol forms (of the three theoretically possible forms) with nonchelated benzene of methoxycarbonyl groups respectively. The form with the nonchelated methoxycarbonyl group predominates in the equilibrium on account of the smaller loss of entropy during its formation compared with the enol containing the nonchelated benzoyl group. The kinetic characteristics of the mutual transformations of the enolic forms in hexachlorobutadiene and nitrobenzene respectively were determined by integration and dynamic nuclear magnetic resonance.
- Research Organization:
- A.A. Zhdanov Leningrad State Univ., USSR
- OSTI ID:
- 6035514
- Journal Information:
- J. Org. Chem. USSR (Engl. Transl.); (United States), Vol. 21:11; Other Information: Translated from Zh. Org. Khim.; 21: No.11, 2263-2268(Nov 1985)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
74 ATOMIC AND MOLECULAR PHYSICS
CARBOXYLIC ACID ESTERS
ISOMERIZATION
NMR SPECTRA
STEREOCHEMISTRY
ENOLS
SYNTHESIS
KETO ACIDS
ACTIVATION ENERGY
BUTADIENE
CARBON 13
CHEMICAL REACTION YIELD
CHEMICAL SHIFT
CHLOROFORM
CONFORMATIONAL CHANGES
COUPLING CONSTANTS
DEUTERIUM COMPOUNDS
ENTROPY
HYDROGEN 1
HYDROGEN TRANSFER
HYPERFINE STRUCTURE
J-J COUPLING
MULTIPLETS
NITROBENZENE
ALCOHOLS
CARBON ISOTOPES
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHLORINATED ALIPHATIC HYDROCARBONS
COUPLING
DIENES
ENERGY
ESTERS
EVEN-ODD NUCLEI
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
INTERMEDIATE COUPLING
ISOTOPES
LIGHT NUCLEI
NITRO COMPOUNDS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHYSICAL PROPERTIES
POLYENES
SPECTRA
STABLE ISOTOPES
THERMODYNAMIC PROPERTIES
YIELDS
400201* - Chemical & Physicochemical Properties
640302 - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory