Abstract: | Conformational analysis of biphenyl-2,2′-diacetate by dynamic NMR and UV spectra and by plots of enzyme activity vs temperature plots is described. From dynamic NMR spectra of the biphenyl-2,2′-diacetate with a chiral shift reagent, the coalescence temperature (Tc), the Gibbs energy of activation (ΔG≠), and the rate coefficient (k) of bipbenyl-2,2′-diacetate were ?5 °C, 59.5 kJ/mol, and 13.3 s?1, respectively. From analysis of the conformational break in the UV spectra and the discontinuity in the plots of enzyme activity vs temperature, the racemerization temperature of bipbenyl-2,2′-diacetate is about 5°C. |