Amyloid fibril dynamics revealed by combined hydrogen/deuterium exchange and nuclear magnetic resonance

2009 ◽  
Vol 385 (2) ◽  
pp. 374-376 ◽  
Author(s):  
Anders Olofsson ◽  
A. Elisabeth Sauer-Eriksson ◽  
Anders Öhman
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Amyloid Fibril ◽  
Deuterium Exchange ◽  
Hydrogen Deuterium Exchange ◽  
Hydrogen Deuterium ◽  
Nuclear Magnetic

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.

scholarly journals Nuclear magnetic resonance studies. XXX.Hydrogen–deuterium exchange in bicyclo[3.2.1] and -[2.2.2]octenes through allylic and vinylic anions

1977 ◽  
Vol 55 (1) ◽  
pp. 50-55 ◽  
Author(s):  
A. K. Cheng ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Deuterium Exchange ◽  
Hydrogen Deuterium Exchange ◽  
Magnetic Resonance Studies ◽  
H Nmr ◽  
Hydrogen Deuterium ◽  
Nuclear Magnetic

Bicyclo[3.2.1]oct-2-ene undergoes hydrogen–deuterium exchange through allyl and vinyl carbanionic intermediates under strongly basic conditions, tert-BuO−/tert-BuOD) at 185 °C. Only allylic exchange had been observed in previous studies with tert-BuO−/DMSO. Since the 2-tert-butoxybicyclo[3.2.1]octanes are stable under these conditions an addition–elimination sequence cannot account for exchange at C-3. The relative rates of exchange at C-2, -3, and -4, and the stereoselectivity at the allylic site were determined by 2H nmr. For comparison, the rate of olefinic exchange in bicyclo[2.2.2]octene was also measured.

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