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CONFORMATIONAL STUDIES OF SELECTED ORGANIC SYSTEMS AS ELUCIDATED BY NUCLEAR RESONANCE SPECTROSCOPY (DELTA-LACTONE, ENOL, STEREOCHEMISTRY, NMR)
Abstract
Different projects are represented by individual chapters (Part I-III). Parts I and II present completed studies, while Part III is incomplete. Part I. Configurational analysis of three isomers (delta)-lactones were conducted. Proton NMR coupling constants gave information on the most likely configuration for these systems. Carbon-13 NMR chemical shifts and observed (gamma)-gauche effects supplemented the proton data. The three isomers (alpha), (beta) and (gamma) were found to adopt different conformation depending on the configuration of the substituents about the lactone plane. IR frequencies in the range 1735-1740cm('-1) were found to be associated with half-chair and or twist-boat conformations. Part II. The keto and two enolic forms of the condensation products of 2,4-pentandione and benzaldehyde were isolated. Carbon-13 and proton NMR studies gave information on the configuration of the three isomers. Molecular mechanics calculation (MM2), supported the NMR data and gave information on the nature of the enolic H-bond. Both NMR and MM2 gave evidence for limited delocalization, which is indicative of lack of "aromaticity" of these enolic systems. Part III. Asymmetric synthesis was attempted using polymers as enzyme analogues. Polymerization of the appropriate monomers were achieved. Chiral cavities were formed via chemical modifications. The oxidant and catalyst were anchored and asymmetric induction attempted on sulfides and alkenes producing sulfoxides and epoxides.
Subject Area
Organic chemistry
Recommended Citation
STANLEY, JEAN AGATHA FULLER, "CONFORMATIONAL STUDIES OF SELECTED ORGANIC SYSTEMS AS ELUCIDATED BY NUCLEAR RESONANCE SPECTROSCOPY (DELTA-LACTONE, ENOL, STEREOCHEMISTRY, NMR)" (1984). ETD collection for University of Nebraska-Lincoln. AAI8504815.
https://digitalcommons.unl.edu/dissertations/AAI8504815