title: Revised Absolute Configuration of Sibiricumin A: Substituent Effects in Simplified Model Structures Used for Quantum Mechanical Predictions of Chiroptical Properties.
abstract: This study discusses the choice of different simplified models used in computations of electronic circular dichroism (ECD) spectra and other chiroptical characteristics used to determine the absolute configuration (AC) of the complex natural product sibiricumin A. Sections of molecules containing one chiral center with one near an aromatic group have large effects on the ECD spectra. Conversely, when the phenyl group is present on a substituent without a nonstereogenic center, removal of this section will have little effect on ECD spectra. However, these nonstereogenic-center-containing sections have large effects on calculated optical rotations (OR) values since the OR value is more sensitive to the geometries of sections in a molecule. In this study, the wrong AC of sibiricumin A was reassigned as (7R,8S,1'R,7'R,8'S)-. Chirality 28:612-617, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Chinese Center for Chirality, College of Pharmacy, Hebei University, Baoding, Heibei, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhao
authors.affiliation: Chinese Center for Chirality, College of Pharmacy, Hebei University, Baoding, Heibei, China.
authors.forename: Zheng-Qiu
authors.initials: ZQ
authors.lastname: Li
authors.affiliation: Chinese Center for Chirality, College of Pharmacy, Hebei University, Baoding, Heibei, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Cao
authors.affiliation: Chinese Center for Chirality, College of Pharmacy, Hebei University, Baoding, Heibei, China.
authors.forename: Miao-Miao
authors.initials: MM
authors.lastname: Liang
authors.affiliation: Department Chemistry, Mississippi State University, State College, Mississippi, USA.
authors.forename: Charles U
authors.initials: CU
authors.lastname: Pittman
authors.affiliation: Chinese Center for Chirality, College of Pharmacy, Hebei University, Baoding, Heibei, China.
authors.forename: Hua-Jie
authors.initials: HJ
authors.lastname: Zhu
authors.affiliation: Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China.
authors.forename: Shi-Shan
authors.initials: SS
authors.lastname: Yu
mesh_terms: D002942:Circular Dichroism; D017705:Lignans / Q000737:chemistry*; D008958:Models, Molecular; D013141:Spiro Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D017705:Lignans; D013141:Spiro Compounds; C000599430:sibiricumin A
keywords: Dft; ECD; absolute configuration; quantum theory; simplified model