This research has investigated the validity of a recently proposed test for distinguishing erythro and threo diastereomers of RCHDCHDX compounds on the basis of temperature dependent nmr spectra. INDO and UMINDO semiempirical molecular orbital calculations were used to calculate all nmr vicinal proton-proton coupling constants of a series of CH3CH2CH2X compounds (X = BH2, CH3, NH2, OH, F, PH2, SH, Cl). These data were used to predict the relative temperature dependence of the time-averaged vicinal proton-proton coupling constants of the corresponding CH3CHDCHDX` compounds.Standard bond lengths and angles were used for the input of trial geometries. Coupling constant data were obtained for molecules with no geometry optimization, optimization of the CH3CCX dihedral angle and total geometry optimization. All results suggest that the proposed test for distinguishing erythro and threo diastereomers of RCHDCHDX compounds is valid.
| Identifer | oai:union.ndltd.org:BSU/oai:cardinalscholar.bsu.edu:handle/181949 |
| Date | January 1979 |
| Creators | Bloss, Richard E. |
| Contributors | Bock, Paul L. |
| Source Sets | Ball State University |
| Detected Language | English |
| Format | 49 leaves : ill. ; 28 cm. |
| Source | Virtual Press |
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