title: Reducing Molecular Flexibility by Cyclization for Elucidation of Absolute Configuration by CD Calculations: Daurichromenic Acid.
abstract: Circular dichroism (CD) calculations of flexible natural products have been difficult because of the large number of low-energy conformers and ambiguous Boltzmann distributions. In this article, through electronic (ECD) and vibrational (VCD) studies on a natural product, (+)-daurichromenic acid, we demonstrate that derivatization of a flexible molecule can dramatically reduce its flexibility. This work also shows the usefulness of derivatization for diminishing computational expenses required for optimization and CD calculations, and for increasing the reliability of the assignment of absolute configuration. Chirality 28:453-459, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Faculty of Advanced Life Science, Frontier Research Center for Post-Genome Science and Technology, Hokkaido University, Sapporo, Japan.
authors.forename: Attila
authors.initials: A
authors.lastname: Mándi
authors.affiliation: Graduate School of Life Science, Hokkaido University, Sapporo, Japan.
authors.forename: Mahadeva M M
authors.initials: MM
authors.lastname: Swamy
authors.affiliation: Faculty of Advanced Life Science, Frontier Research Center for Post-Genome Science and Technology, Hokkaido University, Sapporo, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Taniguchi
authors.affiliation: Faculty of Advanced Life Science, Frontier Research Center for Post-Genome Science and Technology, Hokkaido University, Sapporo, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Anetai
authors.affiliation: Faculty of Advanced Life Science, Frontier Research Center for Post-Genome Science and Technology, Hokkaido University, Sapporo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Monde
keywords: density functional theory; derivatization; electronic and vibrational circular dichroism; elucidation of absolute configuration; reducing flexibility