Physical Sciences and Mathematics Commons^™

Studies On The Size And Non-Planarity Of Aromatic Stacking Moiety On Conformation Selectivity And Thermal Stabilization Of G-Quadruplexes, Mandeep Singh

University of the Pacific Theses and Dissertations

Targeting DNA has the advantage over proteins for cancer remediation because of the fewer copies of the ligands required for the desired therapeutic effect. Traditionally, covalent DNA binders like alkylating agents have been used to induce genetic instability through the formation of DNA lesions and strand breaks, leading to cellular apoptosis. The primary drawback of this treatment is the non-specific binding that affects both cancerous and non-cancerous cells. G-quadruplexes are the DNA secondary structures that are present in abundance near the promoter regions of the oncogenes and are involved in the regulation of their activities. A ligand-mediated stabilization of G-quadruplexes …

Synthesis And Conformational Studies Of Various Amides, Marcos Beltran-Sanchez

University of the Pacific Theses and Dissertations

In the past, aminocyclohexanol rings have been successfully utilized as pH-triggered molecular switches in various trans-2-aminocyclohexanol derivatives. By changing the groups on the amine nitrogen, these models provided a wide pH range in which a switch can occur. The pH-induced switch of conformation was monitored by 1H-NMR spectroscopy. The models were also incorporated into the bilayer membrane of liposome structures and tested for their ability to disrupt their membrane upon their conformational flip induced by a decrease in pH.

In this work, the amide bond has been studied as a molecular switch and various amide derivatives have been tested for …

Kinetics And Stoichiometry Of The Aquation Reaction Of Pentaaquodihalomethyl Chromium(Iii) Ions, Mohammad Javaid Akhtar

University of the Pacific Theses and Dissertations

This study was designed to provide information about the mechanisms of pentaaquodihalomethyl chromium(III) ions (halo chloro, bromo and iodo).

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Mechanisms based on carbonium ion, carbeno and carbenoid type intermediates are proposed. A mechanism based on the nucleophillic attack (S_N2) of water on the carbon center leading to a metal-formyl type intermediate is suggested as best fitting all the criteria observed in these studies.

(see PDF file for additional Abstract as it includes formulas)

Trans Diequatorially Fused Blocking Groups For Glucopyranose Derivatives, Basharat Ali Khan

University of the Pacific Theses and Dissertations

No abstract provided.

Cyclic 4,6-Oxygen-Acetal Derivatives Of D-Glucopyrano-(2,3: 4',5')-2'-Oxazolidinones., Daniel Vernie Robinson

University of the Pacific Theses and Dissertations

No abstract provided.

Attempted Synthesis Of 1-Methyl-4-Isopropyl-Hydroxy Bicyclo (3.1.0) Hexane, Kenny Uzoma Acholonu

University of the Pacific Theses and Dissertations

The purpose of this work was to investigate a general synthetic route to 1-Methyl-4-Isopropyl-Hydroxy Bicyclo (3.1.0) Hexane.

3,3-Diphenyl-2-Morpholinone Derivatives Of 2-Amino-2-Deoxy-D-Allose., Ram Babu

University of the Pacific Theses and Dissertations

A new cyclic protective group has been fused to the cis amino alcohol group of benzyl 2-amino-3,5-o-benzylidene-2-deoxyβ-D-Allopyranoside, by way of a unique rearrangements mechanism. To establish the 2-morpholinone structure, chemical studies, such as reduction and acetylation were conducted.

Comparative spectroscopic studies using ir, pmr, and C-13 nmr confirmed the assigned structures.

The 2-morpholinone ring was cleaved by mild alkaline hydrolysis and could be closed again with acetic anhydride in pyridine. An oxazolidinone derivation of benzyl 2-amino-4,6-o-benzylidene-2-deoxyβ-D-allopyranoside was prepared in a quantitative yield by a modification of a known method.

Protective group properties of the oxazolidinone were studied prior to the …

The Thermal Rearrangement Of Triarylacetonitrile Oxides., Leslie Wayne Gibbs

University of the Pacific Theses and Dissertations

This research is a detailed study of the rearrangement of triarylacetonitrile oxides to the corresponding triarylmethylisocyanates. The kinetics of the rearrangement of triphenylacetonitrlle oxide was followed by infrared absorption spectroscopy using the peak due to the N-0 stretching (1307cm^-1). A study, both, using the differential method (i.e., a plot of the logs of the initial slopes vs. the log of the concentration) and a check of the integrated forms of the rate expressions to determine which gave a constant value for the rate constant showed that the reaction is first order.

From measurements of the rate constant, k, …

Birch Reduction Of Benzamide, N-Substituted Benzamides And Biphenylene, Luther Dickson

University of the Pacific Theses and Dissertations

The Birch reduction of benzamide with sodium and absolute ethanol. 95% ethanol, or tert-butanol in liquid ammonia gave 1,4-dihydrobenzamide in varying amounts. The amide group was not reduced. The two most important variables encountered were the alcohol used and whether or not ammonium chloride was added after the reduction was completed. Without this addition of ammonium chloride, little or no 1,4-dihydrobenzamide was present after workup, while with its addition some 1,4-dihydrobenzamide formed whether the proton source was absolute ethanol, 95% ethanol, or tert-butanol. The highest yield was obtained with tert-butanol with ammonium chloride being added. Addition of ammonium chloride apparently …

Studies Of The Cleavages And Stabilities Of Carbohydrate Epoxides And Epimines, Curtis Alvin Johnson

University of the Pacific Theses and Dissertations

A novel epoxide ring opening of benzyl 3,4-anhydro-2-benzylox-carbonylamido-2-deoxy-β-D-allopyranoside(I) was affected by phenylboronic anhydride in toluene. One of the products was demonstrated to be benzyl 2-benzyloxycarbonylamido-2-deoxy-4,6-0-phenylboronate-β-D-gulopyranoside. Another product isolated, while not identified, had the properties of an anhydro-sugar different from the starting compound(I). Benzyl 6-0-acetyl-2-benzyloxycarbonylamido-2-deoxy-β-D-allopyranoside(II) also underwent epoxide ring opening in a reaction with phenylboronic acid. An isolated product had the properties of a benzyl 2-benzyloxycarbonyiamido-2-deoxy-D-hexoside different from compounds isolate in the reaction of I with the phenyboronate. This indicated the necessity for an unsubstituted 6-OH group in order for the boron compound to be involved in the ring opening. Supporting …

Bromination Of 1,2-Cyclononadiene And 1,3-Dimethylallene, Edward Benny Samuel

University of the Pacific Theses and Dissertations

Much information has been obtained on the orientation of unsymmetrical reagents about substituted allenes. Although hydrogen halide addition to 1,2-propadiene yields 2-halopropenes,^20,31 it has been ample demonstrated, at least in the case of halogenation and oxymercuration of the 1,2-alkyl substituted allenes, that the attacking electrophile ends up in the product attached to the central carbon of the original allenic system. ^{20,22,31,34,38,39,40} Using optically active 1,3-dimethylallene(15) it has been shown that the bromination and oxymercuration of 15 is stereospecific. ^22,39Knowledge of the absolute configurations of the optically active addition products have made it possible to propose a plausible mechanism …

Reactions Of Difunctional Esters With Benzyl 2-Amino-4,6-0- Benzylidene-2-Deoxy-D-Glucopyranosides, Fred Robert Seymour

University of the Pacific Theses and Dissertations

This research is primarily interested in investigating the reactions of benzyl 2-amino-4,6-0-benzylidene-2- deoxy-D-glucopyranoside (I) with various esters. The advantage offered by this sugar is that an alcohol and an amine group are in close proximity, allowing studies of intermolecular vs. intramolecular reactions and observation on anchimeric assistance in intramolecular reactions.

Strained Cycloallenes And Silver Ion Assisted And Unassisted Solvolysis Of Some N,N-Dibromobicyclo(N-3.1.0)Alkanes, Franklin Maurice Boyden

University of the Pacific Theses and Dissertations

The strained cyclic allene intermediates of 1,2-cyclohexadiene, 1,2-cycloheptadiene and 1,2-cyclooctadiene have been successfully generated by the debromination of their corresponding 2,3-dibromocycloalkenes. Evidence for their intermediate existence was obtained by trapping them with the Diels-Alder trapping agent 2,5-diphenyl 1-3,4-benzofuran and by isolating the corresponding addition products.

The goal of this study was to generate the transitory cyclic allenes 1,2-cyclooctadiene, 1,2-cycloheptadiene and 1,2-cyclohexadiene and to investigate some aspects of their chemistry. Evidence for the intermediate existence of these strained cyclic allenes has been found by generating them by the debromination of their corresponding 2,3-dibromocycloalkenes and by trapping the generated cycloallene intermediates with …

Cyclic Derivatives Of 2-Amino-2-Deoxy-D-Hexopyranoses, Kenji Miyai

University of the Pacific Theses and Dissertations

The purpose of this investigation was to prepare heterocyclic derivatives, bridging C-2 and C-3 of 2-amino-2-deoxy-D-hexopyranoses, useful as blocking groups in the preparation of aminosugar oligosaccharides and polysaccharides. The work reported herein is concerned with oxazolidones of 2-amino-2-deoxy-D-hexopyranoses (Figure 1).)

There are no examples known, in which five or six-membered rings are fused in a trans-arrangement to five-membered furanose ring. However, although synthetic difficulties were observed, sic and five-membered rings were fused in a trans-arrangement to a sic-membered pyranose ring as pointed out before. In the case of our trans-diequatorially fused oxazolidones additional preparative difficulties were expected, because of the …

A Short Route To Benzyl Beta-D-Glycosides Of 2-Amino-2-Deoxy-D-Glucose And -D-Allose And Elimination Of The 3-Sulfonate From Benzyl 4,6-O-Benzylidene-2-Benzyloxycarbonylamido-2-Deoxy-3-O-(Methylsulfonyl)- Beta-D-Glucopyranoside, William Denham Rhoads

University of the Pacific Theses and Dissertations

It is one purpose of this dissertation to introduce a facile method for the preparation of β glycosides of D-glucose and D-allose.

It is the second purpose of this dissertation to investigate the preparation of 2-oxazolidinones forming a bridge between C₂ and C₃ of allopyranose. This preparation, along with the facile preparation of β-benzyl glycosides of D-glucosamine and D-allosamine, should lead to compounds which, in a few steps, can conceivably be used for coupling at positions 1 and 4.

A Study Of The Formation Of Cyclic Allenes From 2,3-Dibromocycloalkenes, Michael John Millam

University of the Pacific Theses and Dissertations

This investigation was undertaken in an attempt to form strained cyclic allenes and to study their chemistry. The method chosen for the attempted formation of strained cyclic allenes was the determination of the corresponding 2,3-dibromocycloalkene. 2,3-Dibromocyclononene was synthesized during the course of this investigation so that its debromination to the 1,2-cyclononadiene, which is the smallest stable, 1,2-cycloalkadiene, could be studies as model for the debromination of smaller 2,3-dibromocycloalkenes was initiated. The formation of 1,2-cyclohexadiene was attempted by the debromination of the 2,3-dibromocyclohexene. Evidence for the presence of this unstable intermediate was sought via the use of trapping agents.

Synthesis Of N-Methyl-D-Gulosamine And Methyl Ethers Of N-Methyl-D-Gulosamine, Hazrat Mohammed Noorzad

University of the Pacific Theses and Dissertations

A great variety of amino sugars has been found in antibiotics among these D-gulosamine in the striptomyces group. In the same group, .an N-methylated amino-sugar, N-methyl-L~ glucosamine has been isolated. Although N-methyl-0-gulosamine .has not been found in nature until now, its ultimate discovery would not be surprising in this context. In the present work this amino-sugar and some important derivatives are prepared for the first time, starting from D-glucosamine, a pure benzyl· 3-0-acetyl-2-benzyloxycarbonylamido-2-deoxy-~-D-glucopyranoside (X) was obtained by a series of kno~n processes. Benzyl 3-0-acetyl~-methylsulfonyl-2-deoxy-~-D-glucopyranoside (XIII) and some of its derivatives were obtaine.d from (X). An attempt was made to obtain …

The Synthesis Of Benzyl N-Carbobenzoxy Beta-D-Glucosaminid Uronic Acid Derivatives, Stuart Martin Block

University of the Pacific Theses and Dissertations

The purpose of this research is the preparation and characterization of derivatives of benzyl N-carbobenzoxy-β-D-glucosaminiduronic acid. Previously the derivatives of benzyl N-carbobenzoxy-α-D-glucosaminid-uronic acid have been prepared by H. Weidmann and H. K. Zimmerman (32). The procedure upon which both these uronic acid syntheses is based has been developed with the utilization of platinum in the selective catalytic oxidation of both the benzyl α- and β-D-glucuronosides. The applicability of this research is in the development of new intermediates for the preparation of new diamino sugars or other natural products.

Synthesis Of Benzyl Beta D-Gulopyranosiduronic Acid-(2',3': 4,5)-Oxazolidone-2, Gerald Duane Shryock

University of the Pacific Theses and Dissertations

Although D-glucosamine has been found as a constituent of some antibiotics (28), very little research has been carried out in the area of synthetic preparations. Dutcher (7) recently reviewed the biochemical importance of this class of amino sugars as a constituent of complex antibiotic substances which compose the streptothricin family. For a complete elucidation of these antibiotics, it becomes necessary to investigate thoroughly the synthesis and reactions of the D-glucosamine compounds. Gross et al. (12) have succeeded in preparing the oxazolidone of α-D-glucosamine as well as some derivatives (13) of this compound. The present work reports an attempt to prepare …

A New Two-Position Protecting Group: Preparation And Properties Of Glucopyranosido-(1,2: 4',5')-2'-Oxazolidone And Syntheses Of D-Glucosaminides, Sharad Ramchandra Kulkarni

University of the Pacific Theses and Dissertations

The present work consists of two parts. The first part contains the synthesis of 3,4,6-tri-o-benzoyl-D-glucopyranosido-[1,2:4¹,5¹]-2¹-oxazolidone (III) and the study of its chemistry in order to determine whether it could be used as a simultaneous protecting group for C₁ and C₂ in the preparation of new aminosugars. The second part covers the synthesis and de-o-benzoylation of β-D-glucosaminides. The products thus obtained can be used to prepare new disaccharides. In addition new aminosugar derivatives have been prepared.

The Synthesis Of 2,6-Diamino-2,6-Dideoxy-D-Galactose., Lester Vern Smith Jr.

University of the Pacific Theses and Dissertations

The objectives of this research problem were divided into several parts. The first objective was to develop a practical method of preparing 2,6-diamino-2,6-dideoxy-galactose. A second objective was to investigate the derivatives of benzyl-N-carbobenzoxy-α-D-galactosaminide. FInally, the third objective was to lay the groundwork for another possible route for the synthesis of 2,6-diamino-2,6-dideoxy-galactose other than the uronic acid route.

1,3,5,7-Sym-Hydrindacentetrone And Its Derivatives, Irven Davies

University of the Pacific Theses and Dissertations

Three chapters of this dissertation, therefore,are devoted to describing the synthesis of 1,3,5,7-s-hydrinda-centetrone using the three starting materials, pyromellitic dianhydride by means of the four above described reactions.

1,3,5,7-s-Hydrindacentetrone, itself, and its properties are described in Chapter three when first prepared.

An entire chapter is devoted to the preparation of the dinitroso and dinitro derivatives; both because of the complexity of their reactions and because of their relative importance.

An additional chapter is devoted to other miscellaneous derivatives.

Conclusions have been drawn as to the appropriateness of each method of synthesis and are presented at the end of their respective …