A method for the control of absolute stereochemistry in
morphine syntheses has been demonstrated by the resolution
and efficient racemization of the advanced morphine precursor , 9-methoxy-3-methyl-5,6-dihydro-3H-benzofuro[3,2-e]isoquinoline-
7(7aH)-one, I. This was accomplished by the facile coversion of optically resolved I to its ring opened
form, 5,6,7,8-tetrahydro-10-methoxy-3-methyl-7-oxo[1]benzoxonino[
6,7-c]pyridinium tosylate, II, (Equation...
Two related techniques, based upon ion-exchange solid phase extraction, have been
developed for the determination of arsenic speciation. The inorganic arsenic species
arsenite (As(III)) and arsenate (As(V)) are separated by anion-exchange and detected with
graphite furnace atomic absorption spectrophotometry (GFAAS) with a nickel matrix
modifier. The first separation technique, which...
F1FO-ATP synthase targeting antimicrobials apoptolidin 1 (A1), (+)-erythromefloquine,
and oligomycin were tested in vitro for synergistic minimum inhibitory
concentrations against Staphylococcus aureus. Synergy was strictly defined as inhibition
by at most 25% the MIC of each participating drug. Ampicillin, with an MIC of 0.8
ug/mL, served as a negative control....
Ambifunctional axially chiral 2,2',6,6'-tetrasubstituted biphenyls containing nucleophilic (or basic) functional groups juxtaposed with hydrogen-bond donors were synthesized and their properties studied. Applications for the prepared biaryls as potential organocatalysts for enantioselective carbon-carbon bond forming reactions were examined. Processes investigated included: aldol, Michael, nitroaldol (Henry), and Baylis-Hillman reactions.
The novel amidoamine...
Studies towards the total synthesis of (+)-Phomactin A (1), D (6), and G (9), fungal metabolites with unique molecular architecture and pronounced biological activity, are described. These studies resulted in the synthesis of advanced intermediates 354 and 356, which contain all of the carbon atoms of 1, 6 and 9....
7,7'-Dihydroxy-8,8'-biquinolyl (azaBINOL) was prepared from 7-hydroxyquinoline via N,N-dimethyl O-quinol-7-yl carbamate by directed ortho-metallation followed by FeCl₃-mediated oxidative coupling of the 8-lithioquinoline intermediate. Saponification of the resulting dicarbamate provided crystalline (±)-azaBINOL in 56% overall yield. 6,6'-Bis(dimethylaminocarbonyl)-7,7'-dihydroxy-8,8´-biquinolyl was prepared from the same dicarbamate by a double anionic-Fries rearrangement in 43% yield. 7,7'-Bis(diethylamino-carbonyloxy)-6,6'-diiodo-8,8´-biquinolyl...
The mycosporins, formerly called P310's are secondary metabolites
of fungi closely associated with fungal reproductive processes that
require light. The structurally related iminomycosporins are found in
marine plants and animals and may also have functions related to
light. In this study, approaches toward the asymmetric synthesis of
the mycosporins are...
The design, construction and operation of a fluorometric reaction
rate instrument is described. The instrument is designed for simple
operation with maximum versatility. Advantages and modes of
operation of the system are discussed in detail. The instrument is
used for the kinetics-based determination of trace levels of Ag and Al....
¹³⁰ Sn and ¹²⁸Sn were separated from mixed fission products.
The decay of these isotopes were studied with Ge(Li),
LEPS, and plastic scintillator detector systems in single
and two parameter coincidence modes. The decay scheme constructed
for ¹²⁸Sn decay has levels at 0.0 (5+), 45.7 (4+),
77.8 (3+), 152.9 (2+),...
The development and optimization of a fluorometric reaction
rate method for the determination of aluminum is described.
Modifications to existing instrumentation permit automatic
monitoring and reporting of measurement conditions. Automatic
correction of measured analytical signals is provided if monitored
parameters deviate from optimum values. A computer controlled
standard addition procedure...
The application of lucigenin chemiluminescence for the determination
of trace concentrations of Co(II) is described. This method
is based on the enhancing effect that Co(II) has on the reaction of
lucigenin and hydrogen peroxide in a basic solution. The chemiluminescence
signal from a Co(II) enhanced lucigenin reaction, which is in...
Sulfide is an important species to measure in environmental water samples. The
spectrophotometric detection method for reduced sulfur species (sulfide) based on
generation of methylene blue was adapted to work in an apparatus utilizing microfluidic
PDMS mixing and observation cells with flow channels in the 100 μm range. The
benefits...
An automated instrument based on a single-board microcomputer
was developed for use in voltammetric analyses. Operator input of
numerous experiment parameters allows any type of voltammetric
analysis to be implemented and multiple scans to be run unattended.
A three operational amplifier potentiostat is used to control
the cell voltage and...