I. Reactions of Bicyclo[3.3.0]octenyl Tosylates II. Nitrogen-15 Nuclear Magnetic Resonance Investigations of Organic Reactions

Citation

Nee, Michael Wei-Kuo (1982) I. Reactions of Bicyclo[3.3.0]octenyl Tosylates II. Nitrogen-15 Nuclear Magnetic Resonance Investigations of Organic Reactions. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/82re-5t35. https://resolver.caltech.edu/CaltechTHESIS:05162018-111927806

Abstract

PART I

A. Elimination Reactions of 6-Bicyclo[3.2.0]-2-heptenyl Tosylates

The 6- and 7-bicyclo[3.3.0]-2-octenyl tosylates with 2,4,6-trimethylpyridine have been reported to yield mixtures of bicyclo[3.3.0]octa-2,6-diene and bicyclo[3.3.0]octa-2,7-diene. Under the same conditions, the stereoisomeric 6-bicyclo[3.2.0]-2-heptenyl tosylate gives ring-opened products, 1,3,5-cycloheptatriene and 5-ethylidene-1,3-cyclopentadiene.

B. Acetolysis of Some Bicyclo[3.3.0]-2-octenyl Tosylates

The products of the acetolysis of the stereoisomeric 6-,7-, and 8-bicyclo[3.3.0]-2-octenyl tosylates are reported. These tosylates were themselves stable to skeletal rearrangements, but were found to undergo 1,2-hydride shifts and elimination solvolysis.

PART II

Assignment of the Nitrogen-15 Nuclear Magnetic Resonances of Biotin and Unequivocal Synthesis of (+)-[1-¹⁵N]Biotin

The ¹⁵N NMR spectra of biotin, desthiobiotin, and 2-imidazolidinone were measured. Assignment of the resonances of biotin and desthiobiotin was achieved by off-resonance decoupling. The biotin assignment was confirmed by measurement of biotin specifically labeled with ¹⁵N at N1.

PART III

A ¹⁵N Nuclear Magnetic Resonance Study of the Base-Catalyzed -NH₂ Exchange Reactions of Acetamide and Thioacetamide

The base-catalyzed -NH₂ exchange reactions of acetamide and thioacetamide were studied by ¹⁵N nuclear magnetic resonance spectroscopy by use of line-shape analysis. The ¹⁵N NMR spectra of these primary amides at intermediate exchange rates were broad doublets, which indicated that the two amide protons were exchanging at different rates. The line-shape analysis indicated that the ratio of exchange rates was 6 ± 1 for acetamide and 3 ± 1 for thioacetamide.

PART IV

Determination of the Binding Interactions of cis-[Pt(NH₃)₂Cl₂] with Nucleosides by ¹⁵N Nuclear Magnetic Resonance Spectroscopy

The ¹⁵N NMR chemical shifts and ¹⁵N-¹⁹⁵Pt coupling constants of several platinum(II)-ammine complexes were measured. The magnitude of the coupling constants were dependent on the trans ligand. A similar dependence on the trans ligand was found for the ¹⁵N chemical shifts of the coordinated ammonia ligands. The magnitude of the ¹⁵N platinum coordination shift was proportional to the ¹⁵N protonation shift of the ligand. Cis-[Pt(NH₃)₂Cl₂] was found to bind to guanosine through N7 and another nitrogen site. The drug also binds to N3 of cytidine and to all four of the nitrogen sites of adenosine. No evidence was found to support chelate binding of nucleosides by cis-[Pt(NH₃)₂Cl₂].

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