A practical and versatile instrument has been developed both to
optimize the chemistry of bio- and chemiluminescence reactions and to
measure ultra-trace quantities of associated analytes. The instrument
consists of a pneumatic flow injection system linked to a detection cell and a
signal processing and readout system. The disk-like cell...
Traditional approaches for the direct preparation of alkenes are unable to fully control either the stereochemical configuration of the carbon-carbon double bond or else the regiochemistry of the substituents surrounding it. The recently introduced concept of carbenoid eliminative cross-coupling (CEXC) offers a remedy to these deficiencies by providing for a...
The structural architecture present in marine toxin azaspiracid - 20 stereocenters, 9 rings, 3 separated spirocenters - has attracted considerable synthetic attention. Our efforts toward the synthesis of azaspiracid have led to the completion of both C₁-C₂₆ northern and C₂₇-C₄₀ southern halves. Herein, the
synthesis of southern FGHI ring system...
In the past decades, femtosecond stimulated Raman spectroscopy (FSRS) has been gaining tremendous popularity in fundamental sciences stemming from chemistry to biology. It is capable of capturing both equilibrium and non-equilibrium structural information across a broad range of timescales with simultaneously high temporal and spectral resolutions. Femtosecond transient absorption spectroscopy...
Several types of solid-state inorganic materials are prepared and characterized. By using the SILAR (Successive Ionic Layer Adsorption and Reaction) deposition method in conjunction with hydrothermal dehydration both low-temperature deposition and crystallization of oxide thin films are achieved. Various aspects of new transparent p-type materials are studied by examining both...
The purpose of this project was to study the reactions of 1-(α-pyridyl)-3-buten-1-ol (compound I) and to determine whether or
not the products of some of its reactions are quinolizinium salts.
Reaction of compound I with bromine or iodine yields halide
salts (when no external cooling is applied) instead of the...
1-(2-pyridyl)-3-methyl-3-butene-2-ol was prepared by allowing 2-picolyllithium to react with methacrolein.
In the reaction of picolyllithium with crotonaldehyde, two products 1-(2-pyridyl)-4-methyl-3-butene-2-ol and 1-(2-pyridyl)-4-methyl-2-butene-4-ol were formed.
1-(2-pyridyl)-3-methyl-3-butene-2-ol was subjected to the low
pressure hydrogenation, using methanol as solvent and PtO₂ as catalyst. A red yellow liquid 1-(2-pyridyl)-3-methyl-2-butanol was
obtained. Derivatives of the...
Feeding of [3-¹³C, 2-¹⁵N]arginine, 38a, unequivocally established that the β-
arginine moiety of blasticidin S, 1, was formed from α-arginine by an intramolecular
migration of the α-amino group to the β- position. Further feedings using chirally
deuteriated arginines 38e and 38f revealed that the aminomutase process occurred with
inversion of...
Rapamycin (5) was isolated in 1975 from the soil bacteria Streptomyces hygroscopicus and its structure was determined from spectroscopic techniques and an x-ray crystallographic analysis. Although it was initially found to exhibit antibiotic activity, it was subsequently shown to possess potent immunosuppressive activity as well.
Three approaches to the synthesis...
Studies toward synthesis of subunits of sanglifehrin A, an immunosuppressant featuring a highly substituted [5,5]-spirolactam moiety as well as a 22-membered macrocycle are described. The macrolactone contains a peptidic backbone characterized by an unusual [beta]-substituted (S)-piperazic acid and (S)-m-hydroxyphenylalanine units. These studies resulted in the synthesis of advanced intermediate 358...
Studies towards the total synthesis of (-)-gymnodimine (1), a marine neurotoxin with a unique molecular architecture and pronounced biological activity, are described. These studies resulted in a convergent approach to the advanced intermediate 315, containing the C3-C32 section of 1. Two synthetic routes were developed to construct the tetrahydrofuran subunit...
Several new solid-state inorganic borates have been prepared and
characterized. Single crystals of the simple orthoborate ScB0₃ were
grown and its structure was determined by single-crystal X-ray
methods. The new borates Li₃Sc(B0₃)₂, LaSc₃(B0₃)₄, NdSc₃(B0₃)₄,
SrNaB0₃, and Li4Ln4MB90₂₃ (Ln = Y, Er, and Gd; M = Al and Ga) were
identified...
The plant Senecio jacobaea (tansy ragwort) produces several macrocyclic pyrrolizidine alkaloids which cause irreversible liver cirrhosis. All of the pyrrolizidine alkaloids in Senecio jacobaea are macrocyclic diesters of the necine base retronecine, with the two most predominant being seneciphylline and jacobine. Unlike horses and cattle, sheep and goats are generally...
Early studies on the biosynthesis of Sarubicin A, 1, had suggested the
intermediacy of the novel aromatic amino acid 6-hydroxyanthranilic acid,
17. To investigate the biosynthetic steps beyond 17, [¹³C-¹⁵N carboxamide]
6-hydroxyanthranilamide, 27a, was synthesized, and fed to fermentations
of Streptomyces helicus. Incorporation of 27a into 1 provided suggestive
evidence...
The emphasis of this work has been in two areas of optical materials - the
crystal-chemical development of new optical frequency converters and the synthesis
and study of new hosts for Cr³⁺ luminescence and lasing.
A simple method has been developed to identify promising frequency-doubling
materials containing triangular oxoanions by...
Electrochemical capacitors and batteries are two major electrochemical energy storage technologies, which have been investigated extensively to meet the rapidly-growing demand for higher energy, higher power, lower cost and enhanced safety in the past few decades. With the charge storage mechanism of electrostatic charge adsorption desorption via electrical double layers,...
Bicyclo [6.1.0] non-4-ene was prepared by two routes; (1) reaction
of cis-cis-1, 5-cycloöctadiene with methylene iodide and zinc-copper
couple, (2) sodium-methanol reduction of 9, 9-dibromobicyclo-[6.1.0] non-4-ene. The bicyclononene was characterized by its infrared
spectrum, nuclear magnetic resonance spectrum and common
physical properties. The olefin was hydrogenated to bicyclo [6.1.0] -...
Thermal analysis was used to investigate the following seven
systems: H₂S-B₂F₄, SOF₂-B₂F₄, COC1₂-B₂F₄, SF₄-B₂F₄, Xe-BF₃, NF₃-BF₃, and NF₃-BC1₃. In two of the seven systems
compound formation was observed.
In the system, H₂S-B₂F₄ the compounds H₂S[superscript .]B₂F₄ and
2H₂S[superscript .]B₂F₄ are formed. The compound H₂S[superscript .]B₂F₄ has a melting
point of...
Investigations of plasma production by a pulsed dye laser
microprobe were made. Comparisons between a Q- switched and a
pulsed dye laser system were made on the intensity of the continuum
produced by atmospheric breakdown. The dye laser system was
foundtominimize the production of the continuum which in turn
allowed...
In recent decades, there has been increased attention on human exposure to, and subsequently toxicity of, Polycyclic Aromatic Hydrocarbons (PAHs). PAHs are widespread organic pollutants and some have been shown to be toxic, carcinogenic and mutagenic. This research was focused on understanding the link between global PAH emissions and lung...
The primary focus of this work is on examining structure-property relationships of interest for high-power nonlinear optical and laser crystals. An intuitive and simply illustrated method for assessing the nonlinear optical potential of structurally characterized noncentrosymmetric materials is introduced. This method is applied to materials including common quartz and tourmaline...
A method was developed to quantify organochlorine pesticides in whale scat. This method would ideally replace analysis of pesticides in blood and tissue samples, which are difficult to acquire. Scat samples were collected from one stranded gray whale and three live whales. The samples were extracted with pressurized liquid extraction,...
New syntheses for 2-bicyclo(3.3.1)nonanone and 7-bicyclo-(3.3.1)nonen-2-one were developed. The saturated ketone was prepared
from phenol and acrylonitrile via a novel intramolecular
S[subscript N]2 cyclization process. A Friedel-Crafts cyclization of 3-(3-cyclohexenyl)propanoyl chloride permitted synthesis of the unsaturated
ketone from 4-cyclohexene carboxaldehyde. The formation of
the bicyclo(3.3.1)nonane rather than a bicyclo(3.2.2)nonane skeleton...
Eleven hand specimen whole rock (WR) samples (25-200 g each) and
33 fragments (0.5-0.8 g each) from a single basaltic flow at Picture
Gorge, Oregon were analyzed via instrumental neutron activation
analysis (INAA) for 12 elements (Na, Fe, Cr, Sc, Co, La, Sm, Eu, Yb,
Lu, Hf and Ta). Standard...
White muscle disease or muscular dystrophy of sheep is a selenium
responsive malady common to many areas with an inherent natural
deficiency of selenium in the forage. The disease can be prevented in
lambs by adding trace amounts (approximately 0.1 ppm) of selenium to
the otherwise selenium deficient, forage fed...
In this dissertation, the structural properties, thermodynamics and defect behavior of amorphous metal oxides and polyoxometalates are studied. Amorphous metal oxides have many applications, most notably as a semiconducting material used as the active matrix of thin film transistors. Alas, the amorphous nature of these materials makes studying them rather...
The absorption, translocation and metabolism of a new
herbicide, n-propyl-C¹⁴ N, N-di-n-propyl-thiolcarbamate (PDPC), were
studied in both peanut and soybean plants. These studies were
carried out on plants of different ages and treated at two rates of
application. The residue content of the plants was also determined
from germination to...
The melt intercalation of poly(ethylene oxide) (PEO) between layers of MoO₃ and MPS3 (M=Mn,Cd) is obtained by heating the ground mixture and LiₓMoO₃, KₓMn₁-ₓ/₂PS₃, or KCd₁-ₓ/₂PS₃. The products are characterized by powder X-ray diffraction (XRD). Below the melting temperature of PEO (66 °C), intercalation rates and yields are low. By...
It is the responsibility of humans, as environmental stewards, to monitor our impact on the environment so that efforts can be made to remediate the effects of our actions and change behaviors. To better understand our environmental footprint, sensitive and simple analytical methods are needed to quantify the contaminants that...
The preparation of 4-(3-hydroxypropyl) cyclohexanone and
of 4-(3-hydroxypropyl) cyclohexene and a number of their derivatives
as potential precursors of asymmetrically substituted bicyclo [3, 3, 1]
nonanes is described.
The ketone, 4-(3-hydroxypropyl) cyclohexanone, was prepared
from p-allylanisole by three different routes. Common to each
route was an initial hydroboration-oxidation followed by...
Described herein is the synthesis of an uncharged stereoregular oligonucleotide
analog consisting of cytosine bases linked at specific intervals to a polyamide backbone
derived from (L)-glutamic acid. Preparation of this analog entailed borane reduction of
(L)- pyroglutamic acid to give optically pure lactam alcohol 9. Tosylation and alkylation
with cytosine...
The relative influences of trans-Pacific and regional atmospheric transport on measured concentrations of polycyclic aromatic hydrocarbons (PAHs), PAH derivatives [Nitro- (NPAH) and Oxy-(OPAH)], organic carbon (OC), and Particulate Matter (PM) less than 2.5 μm in diameter (PM₂.₅) were investigated in the Pacific Northwest, USA in 2010-2011. Ambient high volume PM₂.₅...
An instrument was developed which performs analysis of the
oxygen content of air by means of a commercial polarographic oxygen
electrode. The oxygen analyzer is part of a portable instrument
which converts the current from the oxygen electrode into a pulse
whose width is proportional to the oxygen concentration. This...
PART I. The preparation of (-)-ibogamine (1) in fourteen steps from benzoquinone and in 10% overall yield is a powerful illustration of the value of the asymmetric Diels-Alder reaction as a starting point in a multistep synthesis. All four cycloadducts, 70, 77, 84 and 96, obtained with the (S)-BINOL-TiCl₂ complex...
As part of the continuing investigation of the thermal cis- 1, 3, 5-hexatriene to 1,3-cyclohexadiene rearrangement, four new trienes and a cross-conjugated pentaene have been prepared and their thermal reactions studied. A new route to the synthesis of highly substituted trienes has been developed. The synthesis of three of these...
Iodine-129 is a key risk driver at sites where nuclear materials have been fabricated or processed, and it is a predominant isotope of concern in long-term waste storage strategies. I-129 exists primarily as iodate in the subsurface at the Hanford Site in south-central Washington State. Between 15 and 40% of...
In this dissertation, excited state proton transfer (ESPT) and its inhibition in solution and protein environments are revealed using both femtosecond transient absorption (fs-TA) spectroscopy and femtosecond stimulated Raman spectroscopy (FSRS). Using a tunable Raman pump to enhance transient vibrational features of the photoacidic chromophore HPTS in methanol and methanol...
Steroid organoboranes have been found to be useful synthetic
intermediates. Attempted pyrolyses, based on simple trialkylborane
cyclizations, have not yielded C-19 or C-18 functionalized steroids,
but have produced isomerized systems not otherwise available.
Thus, hydroboration of cholesterol followed by pyrolysis at
215° gives 31% of 2-cholestene-6α-ol and 49% of a...
The loss of all deuterium labels from previous feedings of [2-²H]-,
[3,3-²H₂]-, and [2,3,3-²H₃]arginines had indicated the possible intermediacy
of β-hydroxy- and β-ketoarginine (30 and 31, respectively) in the
biosynthesis of the streptolidine portion of streptothricin F (la).
In order to confirm or refute this evidence, D,L-[2,3,3,5,5-²H₅]-
arginine (32) was...
The enantioselective total synthesis of quinolizidine-containing natural product cermizine D and formal syntheses of senepodine G and cermizine C has been achieved. These natural products are members of the lycopodium alkaloids, which have attracted significant attention due to their exciting biological activities and the diverse structural scaffolds. Key steps in...
Femtosecond stimulated Raman spectroscopy (FSRS) is a powerful ultrafast technique which can track photoinduced excited state structural events on femtosecond (fs) to picosecond (ps) timescales. In addition to high temporal and spectral resolutions, FSRS provides a broad spectral window from ca. 100—2000 cm-1 for detection, enabling the direct mapping of...
In this dissertation, my research work on excited state dynamics of small organic molecules in solutions is presented. Using femtosecond stimulated Raman spectroscopy (FSRS) as the main experimental tool, the excited state hydrogen-bonding dynamics (ESHBD) of Coumarin 102, a common laser dye molecule, in ethanol solution is examined with <150...
The first part of this manuscript is about the total synthesis of the Arundo donax bis(indole) natural products. The A. donax alkaloids were prepared using the first example of an ynindole Diels–Alder reaction. Each were then separated, isolated, and determined to have stable enantiomeric conformations at room temperature (Chen, J.;...
An automated on-line ion exchange trace enrichment system has
been developed to improve the detection limits of flame atomic
absorption (AA) spectrophotometry in the determination of trace
metals in natural waters. The sample solution is passed through a
column of Chelex-100 chelating resin by a carrier buffer stream
delivered from...
The extraction of tantalum fluoride complexes by large cationic
extractants (tetraphenylarsonium ion, TPA, and crystal violet) and
by methyl isobutyl ketone (MIBK) has been investigated as a function
of fluoride concentration using ¹⁸² Ta as tracer. Extractions by the
cationic extractants into chloroform were carried out in the absence
of...
Spectrometric detection systems for gas chromatography
(GC) based on gas phase ultraviolet absorbance
and fluorescence measurements have been developed and
evaluated in this research. Polynuclear aromatic compounds
(PNAs) are selectively detected by these systems.
Limits of detection for PNAs range from 4 ng to 90 ng
for absorbance determinations, and...
Aromatic heterocycles are core structural motifs in natural products, pharmaceuticals and biological polymers. Indoles, in particular, represent a significant subclass of aromatic heterocycles, both in terms of sheer numbers, but also in biological and pharmaceutical relevance. As such, new methodologies for the synthesis of indoles represent an important and continually...
Put generally, the work I have conducted in my time at Oregon State University has been to answer two questions. The first of these is “Why do I get this particular product from this particular chemical reaction?” and the second is “How do the reagents in this chemical reaction lead...