TY - JOUR
T1 - Absolute configuration of diterpenoids from Jatropha dioica by vibrational circular dichroism
AU - Burgueño-Tapia, Eleuterio
AU - Chávez-Castellanos, Katia
AU - Cedillo-Portugal, Ernestina
AU - Joseph-Nathan, Pedro
N1 - Publisher Copyright:
© 2016 Elsevier Ltd
PY - 2017
Y1 - 2017
N2 - The absolute configuration of jatropholone A 1 and B 2, including the possibility to observe the vibrational circular dichroism (VCD) capacity to differentiate between two epimeric compounds in the presence of an inherently dissymmetric chromophore, which normally dominates VCD and electronic circular dichroism (ECD) spectra, followed after comparison of their experimental and DFT calculated VCD spectra, allowed us to conclude that although non-local (M/P) chirality generated by atropisomerism dominates over local chirality generated by an (R/S) change, the stereogenic center can confidently be assigned by VCD after DFT calculations. In addition, the absolute configurations of jatrophatrione 3 and citlalitrione 4, a compound proposed as a taxonomic marker for the genus Jatropha, were assigned by contrasting their respective calculated and experimental IR and VCD spectra. The evaluation of Flack and Hooft parameters obtained from the single-crystal X-ray diffraction data of jatropholone B acetate 6, and of 4 independently confirmed the absolute configurations of these molecules.
AB - The absolute configuration of jatropholone A 1 and B 2, including the possibility to observe the vibrational circular dichroism (VCD) capacity to differentiate between two epimeric compounds in the presence of an inherently dissymmetric chromophore, which normally dominates VCD and electronic circular dichroism (ECD) spectra, followed after comparison of their experimental and DFT calculated VCD spectra, allowed us to conclude that although non-local (M/P) chirality generated by atropisomerism dominates over local chirality generated by an (R/S) change, the stereogenic center can confidently be assigned by VCD after DFT calculations. In addition, the absolute configurations of jatrophatrione 3 and citlalitrione 4, a compound proposed as a taxonomic marker for the genus Jatropha, were assigned by contrasting their respective calculated and experimental IR and VCD spectra. The evaluation of Flack and Hooft parameters obtained from the single-crystal X-ray diffraction data of jatropholone B acetate 6, and of 4 independently confirmed the absolute configurations of these molecules.
UR - http://www.scopus.com/inward/record.url?scp=85007275651&partnerID=8YFLogxK
U2 - 10.1016/j.tetasy.2016.11.006
DO - 10.1016/j.tetasy.2016.11.006
M3 - Artículo
SN - 0957-4166
VL - 28
SP - 166
EP - 174
JO - Tetrahedron Asymmetry
JF - Tetrahedron Asymmetry
IS - 1
ER -