Stereochemistry of the palladium catalyzed exchange of deuterium with allylic hydrogens. [Cholest-8(14)-en-3. beta. -ol]
- Univ. of Arkansas, Fayetteville
The stereochemistry of the palladium catalyzed exchange of deuterium with the allylic hydrogens of cholest-8(14)-en-3..beta..-ol,2, has been examined in a test of the Rooney, Gault, and Kemball hypothesis that a ..pi..-allylic surface intermediate is able to react directly with molecular hydrogen. The test compound was selected from evidence that only one face of the double bond is accessible to a catalytic surface. The correlation of mass, /sup 13/C nuclear magnetic resonance, and infrared spectral data shows that no more than one hydrogen atom in each allylic methylene group is replaced (C-7 and C-15). Because the RGK mechanism would require that both hydrogens should be replaced, it cannot be operating in this system. The isomerization of cholest-7-en-3..beta..-ol to 2 is catalyzed in benzene solutions by PdCl/sub 2/(C/sub 6/H/sub 5/CN)/sub 2/ but not by HRh(PPh/sub 3/)/sub 4/, which lends support to the hypothesis that ..pi..-allylic but not ''half-hydrogenated'' intermediates are involved in the related palladium-catalyzed isomerization and exchange reactions of these steroids.
- OSTI ID:
- 7248986
- Journal Information:
- J. Catal.; (United States), Vol. 44:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CONDENSED AROMATICS
ISOMERIZATION
STEREOCHEMISTRY
DEUTERIUM
ISOTOPIC EXCHANGE
PALLADIUM
CATALYTIC EFFECTS
STEROIDS
CHEMICAL REACTION KINETICS
INFRARED SPECTRA
NUCLEAR MAGNETIC RESONANCE
AROMATICS
CHEMICAL REACTIONS
ELEMENTS
HYDROGEN ISOTOPES
ISOTOPES
KINETICS
LIGHT NUCLEI
MAGNETIC RESONANCE
METALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PLATINUM METALS
REACTION KINETICS
RESONANCE
SPECTRA
STABLE ISOTOPES
TRANSITION ELEMENTS
400303* - Organic Chemistry- Isotope Exchange & Isotope Separation- (-1987)
400104 - Spectral Procedures- (-1987)