The potassium salts of certain 1-vinylcycloalk-3-en-l-ols have
been found to undergo sigmatropic ring expansion rearrangements in
HMPA. Preliminary investigations of several benzo-substituted medium
ring systems were undertaken in order to determine which of these
was best suited for further study. A synthetic sequence leading to
the formation of 5-methy1-6-viny1-7,8,9,10-tetrahydro-6-benzocyclo-octenol,
which...
The (±) 8,9:13,14-diseco-norestradiol, a large ring hormone
analog, and its related derivatives, were prepared by a ring expansion
approach. The key step of this approach is the establishment of the
benzocyclododecenone system via the Caubere reaction. This step
not only provides a favorable ring size, it also sets the necessary...
The thermal and anionic rearrangements of substituted 1-vinyltrans-
cyclotridec-3-en-l-ol compounds have been studied to determine
what effects substituents would have on the sigmatropic shift when
placed on the two positions of the 1-vinyl group.
For the thermal rearrangements, the a-substituted vinyl-trans-cyclotridecenols
gave both the [3,3] and [1,3] shift products of...
The potassium salts of a series of 1-vinylcycloalk-3-en-l-ols were found to undergo ring expanding [1, 3]-sigmatropic shifts at 25° when dissolved in hexamethylphosphoramide (HMPA) or 1, 2-dimethoxyethane (DME) with 18-crown-6. The yields and reaction rates were compared with those of the corresponding Siloxy-Cope ring expansions. These anionic cases showed about...
Polybenzimidazoles were synthesized from 3, 3', 4, 4'-tetraminobiphenyl
(diaminobenzidine, or DAB) with orthoesters, carboxylic acid derivatives (an ester and
an acid) and with m-benzenedialdehyde. The products were of low molecular weight,
as evidenced by low inherent viscosity, except in the case of the dialdehyde plus DAB.
The product of that...
Polybenzimidazoles were synthesized from 3,3'-diaminobenzidine (DAB) and dicarboxylic acids. The polymerizations using the dicarboxylic acid monomers were carried out in polyphosphoric acid (PPA) and phosphorus pentoxide/methansulfonic acid (PPMA) which acted as the solvent and condensing agent. The resulting polybenzimidazoles had inherent viscosities in the range of 0.12 to 0.84 dL/g....
A field study on grass field burning was conducted in the
Willamette Valley of Oregon during the summer of 1965. Approximately 243,000 acres of grass fields are burned in the valley during
August and September. Serious air pollution problems result from
this burning. The purposes of the study were to...
A study was conducted to determine what effects the type of
pollutants, storage conditions, storage time, and method of sample
conditioning have on the reported weight of an air pollutant collected
by filtration. Samples were collected from a refuse dump, an arc
furnace smelting nickel ore, and a rotary kiln...