Correlations between ECD spectra and absolute configuration of bridged-ring lactones: Revisiting Beecham’s rule

2021 ◽  
Author(s):  
Jun-Yao Zhang ◽  
Beibei Yang ◽  
Ya-Dong Yang ◽  
Fan Gao ◽  
Wen-Qiang Liu ◽  
...  
Keyword(s):  
Natural Products ◽  
Circular Dichroism ◽  
Absolute Configuration ◽  
Cotton Effect ◽  
Electronic Circular Dichroism ◽  
Circular Dichroïsm

Bridged lactones frequently appear as structural fragments in natural products. To elucidate their stereochemistry using electronic circular dichroism (ECD) spectra, Beecham correlated the sign of the Cotton effect (CE) from...

Enantiopure methoxetamine stereoisomers: chiral resolution, conformational analysis, UV-circular dichroism spectroscopy and electronic circular dichroism

2021 ◽  
Author(s):  
Kun Won Lee ◽  
Ahmed H. E. Hassan ◽  
Youngdo Jeong ◽  
Seolmin Yoon ◽  
Seung-Hwan Kim ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Conformational Analysis ◽  
Absolute Configuration ◽  
Circular Dichroism Spectroscopy ◽  
Chiral Resolution ◽  
Treatment Resistant Depression ◽  
Treatment Resistant ◽  
Electronic Circular Dichroism ◽  
Resistant Depression ◽  
Circular Dichroïsm

Enantioseparation and assignment of absolute configuration of methoxetamine (MXE) enantiopure stereoisomers; a promising novel antidepressant for management of treatment-resistant depression.

scholarly journals Absolute Configuration Sensing of Chiral Aryl- and Aryloxy-Propionic Acids by Biphenyl Chiroptical Probes

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 154
Author(s):  
Stefania Vergura ◽  
Stefano Orlando ◽  
Patrizia Scafato ◽  
Sandra Belviso ◽  
Stefano Superchi
Keyword(s):  
Circular Dichroism ◽  
Absolute Configuration ◽  
Optical Rotation ◽  
Environmental Pollutants ◽  
Red Shift ◽  
Electronic Circular Dichroism ◽  
Configuration Assignment ◽  
Clear Sign ◽  
The Absolute ◽  
Circular Dichroïsm

The absolute configuration of chiral 2-aryl and 2-aryloxy propionic acids, which are among the most common chiral environmental pollutants, has been readily and reliably established by either electronic circular dichroism spectroscopy or optical rotation measurements employing suitably designed 4,4′-disubstituted biphenyl probes. In fact, the 4,4′-biphenyl substitution gives rise to a red shift of the diagnostic electronic circular dichroism signal of the biphenyl A band employed for the configuration assignment, removing its overlap with other interfering dichroic bands and allowing its clear sign identification. The largest A band red shift, and thus the most reliable results, are obtained by employing as a probe the 4,4′-dinitro substituted biphenylazepine 3c. The method was applied to the absolute configuration assignment of 2-arylpropionic acids ibuprofen (1a), naproxen (1b), ketoprofen (1c) and flurbiprofen (1d), as well as to the 2-aryloxypropionic acids 2-phenoxypropionic acid (2a) and 2-naphthoxypropionic acid (2b). This approach, allowing us to reveal the sample’s absolute configuration by simple optical rotation measurements, is potentially applicable to online analyses of both the enantiomeric composition and absolute configuration of these chiral pollutants.

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