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Pyrolysis of cyclohexane and benzene/cyclohexane mixtures in a single pulse shock tubeJohnson, B. Ellen January 2011 (has links)
Photocopy of typescript. / Digitized by Kansas Correctional Industries
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Syntheses and reactions of 1-substituted tricyclo [3.2.1.0.(3,6)] octanes.January 1980 (has links)
Lei Keng Lon. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1980. / Bibliography: leaves 64-69.
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Nucleoside and nucleotide analogues containing fluorineParkinson, Nigel Christopher January 1993 (has links)
The work contained in this thesis is divided into four sections detailing the formation of (diethoxyphosphinyl)difluoromethylene substituted cycloalkanes and alkenes and their chemistry, as well as the syntheses of purine and pyrimidine substituted polyfluoroethers:(i) The methodology for the introduction of the (diethoxyphosphinyl)difluoromethylene group was studied and extended, with specific reference to cyclic systems. The group was successfully introduced into cyclic alkenes with (diethoxyphosphinyl)difluoro- methylene zinc bromide and saturated systems with (diethoxyphosphinyl)difluoromethyl lithium. The organolithium reagent was also shown to be capable of ring opening epoxides to yield alcohols ;(ii) The (diethoxyphosphinyl)difluoromethylene substituted cyclohexene derivative was further functionalised in a four step process to a new class of adenine and guanine based nucleotide analogues. Model studies were carried out on the (diethoxyphosphinyl)- difluoromethylene substituted cyclohexene derivative with a variety of reagents to introduce functionality at the double bond;(iii) The radical addition of (diethoxyphosphinyl)bromodifluoromethane and (diethoxyphosphinyl)difluoroiodomethane to cycloalkenes using ultraviolet photolysis and gamma-ray initiation were successfully carried out, thus opening up a new route into (diethoxyphosphinyl)difluoromethylene substituted cycloalkanes;(iv) The synthesis of purine and pyrimidine nucleoside analogues is described via the coupling of 2-amino-6-chloropurine, 6-chloropurine, silylated 5-fluorouracil and silylated uracil to various α-haloethers. The α-haloethers having previously been synthesised by radical chlorination of both cyclic and acyclic polyfluoroethers.
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Synthesis of compounds of natural and unnatural origin by intramolecular alkylations /Shirley, Neil John. January 1987 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, 1987. / Includes bibliographical references (leaves 213-223).
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Synthetic routes to non-symmetric troponesNavasero, Neenah. January 2006 (has links)
No description available.
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Synthesis of compounds of natural and unnatural origin by intramolecular alkylationsShirley, Neil John. January 1987 (has links) (PDF)
Bibliography: leaves 213-223.
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Synthetic routes to non-symmetric troponesNavasero, Neenah. January 2006 (has links)
The synthesis of substituted non-symmetric tropones has proven to be a considerable synthetic challenge. Particularly, a 3,4,6-tnsubstituted tropone which is required for the total synthesis of CP-225,917 is currently being undertaken by our group. / Two approaches towards the synthesis of substituted tropones are presented. Both utilize linear diene precursors which are closed to 7-membered cycloheptene rings via ring closing metathesis. In the first method, linear precursors are synthesized by addition of nucleophilic substituents to carbonyl groups to form alcohol groups. After forming the cycloheptene ring, the alcohol groups are eliminated to form the tropone. The second method uses an oxidation protocol to form a,(3-unsaturation on either side of a cycloheptenone precursor. An attempt towards the synthesis of the desired tropone required for the CP-225,917 synthesis is also presented. / The methods described here use simple inexpensive starting materials and provide access to tropone substitution not readily available through other means.
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Synthetic and Structural Studies on the Novel Formation of Bicyclo[n.2.0]alkan-1-olsMcCleary, Michelle Angela, n/a January 2004 (has links)
Reaction of phenyl vinyl sulfoxide with the lithium enolates of simple ketones of varying ring size (cyclopentanone, cycloheptanone and cyclooctanone) under controlled cyclisation conditions followed by subsequent oxidation resulted in the formation of the bicyclo[n.2.0]alkan-1-ols 253-255, 262, 263, 265, 268 and 269 in conjunction with alkylated species 256, 257, 264, 266 and 267. The ratio of bicyclo[n.2.0]alkan-1-ols to alkylated ketone formation observed was dependent on a number of factors including the variation of enolate reactivity between the different ring sizes, conversion of phenyl vinyl sulfoxide, time, temperature and concentration of reaction and the stability and steric strain observed in the final bicyclo[n.2.0]alkan-1-ol product. X-ray crystal structures of 253, 262 and 265 were obtained and a structural study showed that as the overall steric strain in the bicyclo[n.2.0]alkan-1-ol product is decreased there is a corresponding increase in product distribution in favour of bicyclo[n.2.0]alkan-1-ol formation in conjunction with increased yields. Selected substituted and functionalised ketones (2-methylcyclopentanone, 2,6-dimethylcyclohexanone, 2-methylcyclohexanone and 1,4-cyclohexanedione mono-ethylene ketal) also reacted in the cyclisation reaction to give bicyclo[n.2.0]alkan-1-ols 270, 271, 277, 278, 281, 282, 285 and 286 in conjunction with alkylated products 272, 279, 280, 283, 284 and 287. Incorporation of substitution at the bridgehead and C2 position had a role in the preference of the major stereochemical isomer observed for a bicyclo[n.2.0]alkan-1-ol (n = 3, 4). A structural comparison of the X-ray crystal structures of 278, 281 and 286 indicated that the pseudo chair conformation of the six-membered ring influenced ring torsion and bond angles in the bicyclo[4.2.0]octanol ring system. Two model studies were selected to illustrate the potential application of the cyclisation process as methodology towards natural product synthesis or complex ring systems. No bicyclo[n.2.0]alkan-1-ol formation was evident in an intramolecular example using the starting ketone 291 in which the electrophile is tethered to the ketone. 2,6-Dimethyl-2-cyclohexen-1-one 301 considered as a model study towards the synthesis of the antibiotic mellolide, upon reaction with phenyl vinyl sulfoxide and oxidation displayed poor reactivity. The novel bicyclo[2.2.2]octanones 303, 304 and 305 were formed in very low yields. The lack of reactivity of the ketones 2,6-dimethyl-2-cyclohexen-1-one, 1,2-cyclohexanedione and 1,4-cyclohexanedione towards bicyclo[n.2.0]alkan-1-ol formation suggested that conjugation in the enolate prior to reaction with phenyl vinyl sulfoxide was not favourable. The non-reactivity of these ketones and the hindered ketone camphor indicated the potential limitations to the cyclisation methodology. However, conversion of the ketal functionality of 286 to a ketone resulted in the formation of the functionalised bicyclo[4.2.0]octanol 288 providing positive indications for further synthetic applications.
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Synthesis of compounds of natural and unnatural origin by intramolecular alkylations / by Neil John ShirleyShirley, Neil John January 1987 (has links)
Bibliography: leaves 213-223 / viii, 224 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Organic Chemistry, 1987
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Natural product synthesis via cyclobutanes : part I, Asymmetric synthesis of (+)-byssochlamic acid, part II, An approach to the nootropic agent huperzine AKim, Jungchul 02 November 2000 (has links)
PART I. Asymmetric syntheses of both natural (+)- and nonnatural (-)-
byssochlamic acid via a [2+2] photoaddition-cycloreversion strategy are
described. X-ray crystallographic analysis of the cyclohexylamine salt 99 showed
that the structure of the monomethyl ester 100 from esterase hydrolysis of 44
was originally misassigned as 56. The enantiomeric relationship of the two
diolides 106 and 70 permitted syntheses of nonnatural byssochlamic acid (-)-3
and natural byssochiamic acid (+)-3 from enantiopure alcohol (+)-64 and from its
enantiomer (-)-110, respectively. Through the use of (��)-103 to reach both
enantiomers of byssochlamic acid (3) and subsequent epimerization of the npropyl
chain, it was proved that the cis configuration of the two alkyl substituents
is strongly preferred in the natural product.
PART II. An asymmetric approach towards the nootropic agent huperzine A
is described. Formation of cyclobutane 122 with the desired stereochemistry was
accomplished using intramolecular [2+2] photoaddition of the enantiopure enone
121. Attempts to prepare the methoxypyridine system via an azadiene Diels-
Alder reaction were unsuccessful. However, intramolecular Michael addition of
181 produced silyl ether 182 which was converted into the pyridone 187 by
treatment with hydrogen fluoride followed by selenoxide elimination. Attempts to
effect the key sigmatropic rearrangement of ketone 197 into a direct precursor of
huperzine A were unsuccessful. / Graduation date: 2001
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