Hydrogen/deuterium exchange in alkyl-hydride derivatives of ansa-tungstenocene compounds

Polyhedron ◽  
2005 ◽  
Vol 24 (11) ◽  
pp. 1388-1403 ◽  
Author(s):  
Malcolm L.H. Green ◽  
Stephen L.J. Conway ◽  
Linda H. Doerrer
Keyword(s):  
Deuterium Exchange ◽  
Hydrogen Deuterium Exchange ◽  
Hydrogen Deuterium ◽  
Derivatives Of ◽  
Alkyl Hydride

Nuclear magnetic resonance studies. XXXII. Rearrangement, isomerization, and deuterium exchange via β-enolization in bicyclooctenones. A 2H nuclear magnetic resonance study

1978 ◽  
Vol 56 (10) ◽  
pp. 1342-1347 ◽  
Author(s):  
A. K. Cheng ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nuclear Magnetic Resonance Study ◽  
Deuterium Exchange ◽  
Hydrogen Deuterium Exchange ◽  
Group Comparison ◽  
Magnetic Resonance Study ◽  
Hydrogen Deuterium ◽  
Derivatives Of ◽  
Nuclear Magnetic

The equilibration of the α,α -diniethyl derivatives of bicyclo[2.2.2]octenone, bicyclo[3.2.1]-oct-2-en-6-one, and its Δ3 isomer has been examined at 155 and 185 °C in tert-BuO−/tert-BuOH. Using 2Hmr spectroscopy the rates and stereoselectivity of hydrogen–deuterium exchange in each of these ketones have been determined for equilibrations with tert-BuOD as solvent. The relative reactivities for exchange at the allylic and vinylic sites compared to the analogous results for the corresponding olefins reveal a significant activating effect of the carbonyl group. Comparison of the data with those for the corresponding saturated ketones shows that the double bond enhances the rate of isomerization appreciably and increases the bias of the equilibrium toward the [3.2.1] skeleton.

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