Direct determination of absolute configuration of methyl-substituted phenyloxiranes: combined experimental and theoretical approach.
Three possible methyl-substituted phenyloxiranes have been synthesized in enantioenriched form (89-99% enantiomeric excess (ee)), and their vibrational absorption (VA) and vibrational circular dichroism (VCD) spectra have been recorded. The experimental spectra are compared to theoretical spectra obtained from quantum mechanical calculations (density functional theory with the B3LYP hybrid exchange correlation functional with 6-31++G*, aug-cc-pVDZ, or aug-cc-pVTZ basis set) and related to the physical structure of the compounds. The absolute configuration could be established directly in each case by comparing experimental and theoretical spectra. In addition, we have been able to document the changes that occur both in structures and in the VA and VCD spectra due to substituent effects on the oxirane ring.
Fristrup
Peter
P
Center for Sustainable and Green Chemistry, Department of Chemistry, Technical University of Denmark, Building 201 Kemitorvet, DK-2800 Kgs. Lyngby, Denmark. pf@kemi.dtu.dk
Lassen
Peter R
PR
Johannessen
Christian
C
Tanner
David
D
Norrby
Per-Ola
PO
Jalkanen
K J
KJ
Hemmingsen
Lars
L
D004852:Epoxy Compounds / Q000737:chemistry*; D007536:Isomerism; D008745:Methylation; D008958:Models, Molecular; D015394:Molecular Structure; D013057:Spectrum Analysis
D004852:Epoxy Compounds; C013690:styrene oxide