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STEREOCHEMISTRY OF SELECTED ORGANIC SYSTEMS AS ELUCIDATED BY NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY

DIANA GREGSTON KRUGER, University of Nebraska - Lincoln

Abstract

Different projects are represented by individual chapters (Parts I-IV). Parts I-III present completed studies, whereas Part IV contains successful experimentation which did not culminate in a finished study. Part I. A Carbon-13 and Proton NMR Study of Various Multisubstituted Pyridines and Pyridones. Several multisubstituted pyridines and multisubstituted pyridones are studied extensively. Long range coupling constants (two and three bond J), one bond coupling constants (('1)J), as well as chemical shift assignments in proton and carbon-13 nmr are used to elucidate information about the heterocyclic aromatic ring. The effect of multiple substitution on additivity relationships is found to vary from predicted values for chemical shift data, as well as for coupling constant data. Part II. A Relaxation Time (T(,1)) Study Designed to Examine the Mechanism of Oxygen Entrainment by Perfluorohexane. Perfluoroalkanes are known to complex oxygen very efficiently; they have been used as "synthetic blood". By observing relaxation times of individual carbons in the chain, the mechanism for entrapment of oxygen is found to be due to a dissolution effect. The cavities in the solution are filled with oxygen, and comparing the size of the cavities in perfluorohexane (large) to the cavities in a similar hydrocarbon (small), a difference in the rates of relaxation should be apparent. The relaxation rates for perfluorohexane are much higher than the relaxation rates for heptane. Part III. Asymmetric Induction in Carbonyl Analogues. Two similar prochiral alkenes are reacted with a series of RMgX, RLi, and R(,2)CuLi reagents, and the asymmetric induction is determined in each case. The diastereomeric product ratios are extracted from proton and carbon-13 nmr spectra. The diastereomeric pairs are separated into individual components whenever possible, and stereochemical assignments are made on the isolated compounds according to nmr data. Part IV. Miscellaneous. A brief description of incomplete projects is presented. The only references included for this section are those which detail experimental procedure. In essence, the entire section is experimental; a very brief introduction for each project is presented, the successful experimental procedures are outlined, and a short conclusion is included.

Subject Area

Organic chemistry

Recommended Citation

KRUGER, DIANA GREGSTON, "STEREOCHEMISTRY OF SELECTED ORGANIC SYSTEMS AS ELUCIDATED BY NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY" (1981). ETD collection for University of Nebraska-Lincoln. AAI8208360.
https://digitalcommons.unl.edu/dissertations/AAI8208360

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