title: Synthesis and Stereochemical Assignment of Crypto-Optically Active (2) H6 -Neopentane.
abstract: The determination of the absolute configuration of chiral molecules is at the heart of asymmetric synthesis. Here we probe the spectroscopic limits for chiral discrimination with NMR spectroscopy in chiral aligned media and with vibrational circular dichroism spectroscopy of the sixfold-deuterated chiral neopentane. The study of this compound presents formidable challenges since its stereogenicity is only due to small mass differences. For this purpose, we selectively prepared both enantiomers of (2) H6 -1 through a concise synthesis utilizing multifunctional intermediates. While NMR spectroscopy in chiral aligned media could be used to characterize the precursors to (2) H6 -1, the final assignment could only be accomplished with VCD spectroscopy, despite the fleetingly small dichroic properties of 1. Both enantiomers were assigned by matching the VCD spectra with those computed with density functional theory.
authors.affiliation: The Mallat Family Laboratory of Organic Chemistry, Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa, 32000 (Israel).
authors.forename: Ahmad
authors.initials: A
authors.lastname: Masarwa
authors.affiliation: Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, 35392 Giessen (Germany).
authors.forename: Dennis
authors.initials: D
authors.lastname: Gerbig
authors.affiliation: The Mallat Family Laboratory of Organic Chemistry, Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa, 32000 (Israel).
authors.forename: Liron
authors.initials: L
authors.lastname: Oskar
authors.affiliation: The Mallat Family Laboratory of Organic Chemistry, Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa, 32000 (Israel).
authors.forename: Aharon
authors.initials: A
authors.lastname: Loewenstein
authors.affiliation: Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, 35392 Giessen (Germany).
authors.forename: Hans Peter
authors.initials: HP
authors.lastname: Reisenauer
authors.affiliation: ICCMMO (RMN en Milieu Orienté), Université Paris-Sud, CNRS UMR 8182, Bât. 410, 15 rue Georges Clemenceau, 91405 Orsay (France). philippe.lesot@u-psud.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Lesot
authors.affiliation: Institute of Organic Chemistry, Justus-Liebig University, Heinrich-Buff-Ring 58, 35392 Giessen (Germany). prs@uni-giessen.de.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Schreiner
authors.affiliation: The Mallat Family Laboratory of Organic Chemistry, Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa, 32000 (Israel). chilanm@tx.technion.ac.il.
authors.forename: Ilan
authors.initials: I
authors.lastname: Marek
mesh_terms: D008968:Molecular Conformation; D010420:Pentanes / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D010420:Pentanes; C039752:neopentane
keywords: NMR spectroscopy; chirality; cryptochirality; neopentane; vibrational circular dichroism