A synthetic approach toward the two major fragments of cathedulin K-19,
euonyminol (4) and dimethyl cathate (69), was investigated. Synthesis of
dimethyl cathate was accomplished in 3 steps starting from 73. Efforts directed
towards the synthesis of euonyminol, a highly oxygenated dihydroagarofuran
sesquiterpene, was advanced to a stage in which...
Grid-scale energy storage systems are urgently needed to increase the flexibility and rigidity of the grid for modern society and take full advantage of the renewable green energy resources such as solar energy and wind energy. Na-ion batteries (NIBs) and K-ion batteries (KIBs) have been emerged as one of the...
Major and minor minerals have been separated from
three L-6 chondritic meteorites (Alfianello, Colby (Wisconsin),
and Leedey). Olivine, hypersthene, diopside, feldspar,
troilite, chromite, phosphate minerals, and metallic
minerals were analyzed for major, minor and trace elements
using instrumental neutron activation analysis and radiochemical
neutron activation analysis techniques. Concentrations
df the...
Molecular chirality plays a critical role in chemistry, biology, and medicine. To study and better understand conformational chirality, it is necessary to obtain structurally interesting molecules that exhibit this form of chirality. Our lab utilizes total synthesis and methodological development to obtain conformationally chiral natural products of interest. We believe...
The Diels-Alder reaction represents a promising tool for use in
asymmetric synthesis. The reaction involves a rigid transition state
that facilitates the formation of one diastereomeric transition state
and is reversible. This satisfies two necessary criteria for
asymmetric synthesis.
The Diels-Alder reactions of 1,l-dialkylspiro[2.4]-4,6- heptadienes
with maleic anhydride and p-benzoquinone...
Ambient high-volume (hi-vol) air samples were collected between March 15th and May 30th 2002, at Cheeka Peak Observatory (CPO), located on the tip of the Olympic Peninsula, Washington State. This sampling campaign was in conjunction with the 2002 Inter-Continental Transport and Chemical Transformation (ITCT 2K2) Campaign and the Photochemical Ozone...
Many pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers
(PBDEs), and polycyclic aromatic hydrocarbons are persistent, bio-accumulative, and
toxic. These semi-volatile organic compounds (SOCs) can undergo atmospheric
transport and deposition in cold, remote ecosystems. A better understanding of their
accumulation in the fish of these ecosystems is important to better predict...
Dearomatization reactions exist broadly in biosynthesis and chemical synthesis. The highly functionalized atoms of arenes can be masked by it aromaticity, and upon dearomatization, those reactive atoms can be readily applied to bond formation and further manipulation. The total synthesis of (–)-cephalotaxine and (–)- homoharringtonine is described via an oxidative...
The photochemistry of aldicarb and two related compounds,
0-(methylcarbamoyl) isobutyraldehyde oxime and 0-(methylcarbamoyl)
trimethylacetaldehyde oxime was explored under laboratory
conditions. Upon irradiation aldicarb decomposed rapidly to
methylamine, dimethylamine, tetramethylsuccinonitrile, and
1-methylthio-2, 3-dicyano-2, 3-dimethylbutane. The other two
compounds decomposed only after a long period of irradiation. The
difference in reactivity was...