Chiral recognition of diastereomeric 6‐cedrols by vibrational circular dichroism

Abstract

The use of vibrational circular dichroism spectroscopy for the chiral recognition of the two epimers of 6-cedrol, tricyclic sesquiterpenes, which contains oxygen as the heaviest atom, is shown. Bands in the 1500-850 cm(-1) region of the spectra were analyzed to calculate the anisotropy factors (g), which provided the regions of maximum circular dichroism effect for each epimer.

Recent advances in the use of vibrational chiroptical spectroscopic methods for stereochemical characterization of natural products

“…Its absolute conguration was assigned as 4S,5S,7S,8S,10R,11R by VCD measurements in comparison to calculations at the B3LYP/DGDZVP level. 108 Conformational analysis of the sesquiterpene benzoquinones (R)-perezone (57) and (R)-dihydroperezone (58) using VCD and DFT (B3LYP/DGDZVP) calculations suggested analogous conformations for both molecules and confronted previous reports on the presence of weak p-p interactions between the alkyl chain double-bond and the quinone ring in 57. 98 The conformational landscapes of compounds 5, 67 7, 99 and (À)-(S)-limonene oxide (42), 100 a secondary metabolite and atmospheric pollutant, were probed by VCD and quantum chemical calculations.…”

Stereochemical analysis of (+)-limonene using theoretical and experimental NMR and chiroptical data

“…Although VCD spectra can be much more difficult to interpret for assigning the absolute configuration, a number of studies have been published in the area of natural product analysis (e.g. Gordillo-Rom an et al) [67]. The very active research group of Avil es Moreno especially deals with the VCD analysis of natural products, such as limonene oxide [68] and carvone [69].…”

Elucidation of the absolute configuration of rhizopine by chiral supercritical fluid chromatography and vibrational circular dichroism

“…Despite experimental and theoretical challenges, VCD has become one of the premier methods for the determination of the AC of chemical compounds. The number and complexity of structures analyzed more or less routinely continually increases , making VCD a method of choice for AC determination of complex natural products such a rhizopine.…”