Studies in Stereochemistry

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The chemical and physical properties of molecules are determined not only by their elemental composition, but also by their shape (stereochemistry). These studies will provide further information on the role of shape in controlling chemical properties. This is particularly important in understanding how molecules interact in biological systems. The specific stereochemical studies of this project are in four areas: (A) Conformational Analysis - The conformational behavior of 1,2,3,4-N-methyltetrahydroquinolines and their salts will be studied as well as the relation of optical rotation to conformation and hydrogen bonding in cis-3-hydroxythiane sulfoxide and other compounds; (B) NMR Spectroscopy - NMR spectroscopic studies will deal with O-17 NMR, especially effects of hydrogen bonding, application to mechanistic studies and spectra of sugar derivatives; (C) Asymmetric Synthesis - The studies in asymmetric synthesis will involve the previously investigated 1,3-oxathiane system and will also encompass methodological studies of chiral 1,3-oxazanes as molds for stereoselective syntheses. Further, mechanistic studies of the importance of chelation in such studies involving Cram's cyclic rule will be undertaken by stop-flow methods; and (D) Carbanion Chemistry - The carbanion studies will involve carbanions derived from 1,3-oxathiane and 1,3-dioxane and will encompass efforts to investigate their rate of inversion by stop-flow nmr.