1262977-18-3Relevant academic research and scientific papers
Circular dichroism, optical rotation and absolute configuration of 2-cyclohexenone-cis-diol type phenol metabolites: Redefining the role of substituents and 2-cyclohexenone conformation in electronic circular dichroism spectra
Kwit, Marcin,Gawronski, Jacek,Boyd, Derek R.,Sharma, Narain D.,Kaik, Magdalena
, p. 5635 - 5645 (2010)
The absolute configurations of 2-cyclohexenone cis-diol metabolites resulting from the biotransformation of the corresponding phenols have been determined by comparison of their experimental and calculated circular dichroism spectra (TDDFT at the PCM/B2LYP/Aug-cc-pVTZ level), optical rotations (calculated at the PCM/B3LYP/Aug-cc-pVTZ level) and by stereochemical correlation. It is found that circular dichroism spectra and optical rotations of 2-cyclohexenone derivatives are strongly dependent on the ring conformation (M or P sofa S(5) or half-chair), enone non-planarity and the nature and positions of the hydroxy and alkyl substituents. The effect of non-planarity of the enone chromophore, including the distortion of the CC bond, is determined for the model structures by TDDFT calculations at the PCM/B2LYP/6-311++G(2d,2p) level. Non-planarity of the CC bond in the enone chromophore is commonly encountered in 2-cyclohexenone derivatives and it is a source of significant rotatory strength contribution to the electronic circular dichroism spectra. It is shown that the two lowest-energy transitions in acrolein and 2-cyclohexenone and its derivatives are nCO-πCO* and πCC-πCO*, as expected, while the shorter-wavelength (below 200 nm) transitions are of more complex nature. In 2-cyclohexenone and its alkyl derivatives it is predominantly a mixture of πCC-πCC* and πCC-σ* transitions, whereas the presence of hydroxy substituent results in a dominant contribution due to the nOH-πCO* transition. A generalized model for correlation of the CD spectra of 2-cyclohexenones with their structures is presented.
Dioxygenase-catalysed cis-dihydroxylation of meta-substituted phenols to yield cyclohexenone cis-diol and derived enantiopure cis-triol metabolites
Boyd, Derek R.,Sharma, Narain D.,Stevenson, Paul J.,Blain, Marine,McRoberts, Colin,Hamilton, John T. G.,Argudo, Jose M.,Mundi, Harpinder,Kulakov, Leonid A.,Allen, Christopher C. R.
experimental part, p. 1479 - 1490 (2011/04/23)
cis-Dihydroxylation of meta-substituted phenol (m-phenol) substrates, to yield the corresponding cyclohexenone cis-diol metabolites, was catalysed by arene dioxygenases present in mutant and recombinant bacterial strains. The presence of cyclohexenone cis-diol metabolites and several of their cyclohexene and cyclohexane cis-triol derivatives was detected by LC-TOFMS analysis and confirmed by NMR spectroscopy. Structural and stereochemical analyses of chiral ketodiol bioproducts, was carried out using NMR and CD spectroscopy and stereochemical correlation methods. The formation of enantiopure cyclohexenone cis-diol metabolites is discussed in the context of postulated binding interactions of the m-phenol substrates at the active site of toluene dioxygenase (TDO). The Royal Society of Chemistry 2011.
