A unique mass-flow control system for the carrier gas
in gas chromatography is described and evaluated. Carrier
gas flow is controlled by a flow sensor, feedback electronics,
a flow-control valve and a microcomputer. The
flow-rate is monitored by a mass-flow meter by this system
and the flow is adjusted in...
Intramolecular cyclization of organometallic compounds represents
a promising tool for synthesis. The reaction involves exothermic
consumption of intramolecular double bonds via insertion
into a carbon metal sigma bond. This represents an intramolecular
example of the reaction type responsible for metal catalyzed polymerization
of olefins.
Organolithium reagents were found to cyclize...
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 question of why carboxylic acids and phenols are stronger
acids than alcohols has been investigated experimentally and theoretically.
The experimental approach involves comparison of gas-phase
acidities and core-ionization energies. The theoretical treatment uses
calculated point potentials and acidities.
The ease of proton removal is related to two factors known...
Steroid carbenes have been investigated as synthetic intermediates.
Basic decomposition of 4-en-3-one tosylhydrazones (and
other A-ring systems) gives varying amounts of 2, 4-dienes, and
solvent derived products with diglyme, heptane, tetrachloroethylene,
carbon tetrachloride, benzene and cyclohexene. A method for
separating complex product mixtures was developed and a study of
the...
A high-spectral resolution laser-excited molecular fluorescence
system was developed that utilizes a pulsed supersonic expansion to
simplify the fluorescence excitation spectra of large, gas-phase
aromatic molecules diluted in an excess of a monatomic gas. A
microcomputer was used to control and synchronize the instrumental
components, which included a Chromatix CMX-4...