Where did the elements come from? Why are they found in the abundance that they are? These are two of the fundamental questions that the field of astrophysics has sought to answer. The first major studies of elemental synthesis were done in the 1950's and 1960's. Most notable among them was the Burbidge, Burbidge, Fowler, and Hoyle paper [Clayton 73]. This paper set forth the general theory of elemental synthesis in stars and supernovae by means of nuclear reactions. It remains the leading theory for elemental abundance today.As with most theories, the picture of elemental synthesis remains incomplete. While it is thought that the overall theory is correct, there are still many mysteries in the details. There are several kinds of nuclear reactions that occur in stars and supernova that create the elements heavier than iron. They include the r-process, s-process, and p-process, along with several others. However, there are some elements whose creation is not fully understood. There are a variety of reasons for this, which will be discussed.In our experiment we studied the nuclear reaction properties of an isotope of Copper (65Cu). It is theorized that it is produced by the p-process during a supernova explosion. The p-process can be described simply as the collision of an alpha particle with a large atomic nucleus with a proton byproduct. Little actual experimental data has been taken involving the p-process, which is why we chose this reaction. The experiment was done using the Tandem Van de Graaff Accelerator at Ohio University. / Department of Physics and Astronomy

The synthesis of 7-acetyl-11'-benzyloxylavendamycin methyl ester (47), 7acetyl-11'-hydroxylavendamycin methyl ester (48), 11'-hydroxylavendamycin methyl ester (49), 11'-benzyloxylavendamycin methyl ester (50), are described. Pictet-Spengler condensation of 7-N-acetyl-2-formylquinoline-5,8-dione (26) with 5-benzyloxytrytophan methyl ester (45) or 5-hydroxytryptophan methyl ester (46) in dry xylene or anisole directly afforded lavendamycin analogs 47 or 48. Compound 49 was obtained by hydrolysis of 48 with 70% H2SO4 - H2Osolution. Compound 50 was obtained by hydrolysis of 47 with sodium carbonate solution.Aldehyde 26 was prepared according to the following general procedure. Nitration of 8-hydroxy-2-methylquinoline (28) yielded 8-hydroxy-2-methyl5,7-dinitroquinoline (29). Compound 29 was then hydrogenated and acylated with acetic anhydride to yield 5,7-bis(diacetamido)-8-hydroxy-2methylquinoline (31). Compound 31 was oxidized to give 5,8- dione 25 by using potassium dichromate. Treatment of compound 25 with selenium dioxide in refluxing 1,4-dioxane yielded compound 26.3 (Isopropylaminoethylidene)-6,7-dimethoxyindole (39) was prepared via the following procedure. Acylation of vanillin (32) with acetic anhydride yielded acetylvanillin (33). Compound 33 was nitrated and hydrolyzed to give 2nitrovanillin (35). Compound 35 was then methylated using dimethyl sulfate to produce 2-nitroveratric aldehyde (36). Condensation of compound 36 with nitromethane yielded 3,4-dimethoxy-2-f3-nitrostyrene (37). Ammonium formate reductive cyclization of compound 37 in refluxing methanol in the presence of a catalytic amount of 10% palladium on charcoal yielded 6,7dimethoxyindole (38). Electrophilic substitution reaction of compound 38 with ethylideneisopropylamine (41) in dry toluene yielded compound 39.Methyl (2RS, 3SR)-2-amino-3-[3-(5-benzyloxyindolyl)]butanoate (45) and methyl (2RS, 3SR)-2-amino-3-[3-(5-hydroxyindolyl)]butanoate (46) were obtained following the procedure described below. Electrophilic substitutionreaction of 5-bezyloxyindole (40) with ethylideneisopropylamine (41) in dry toluene yielded 3-(isopropylaminoethylidene)-5-benzyloxyindole (42). Condensation of compound 42 with methyl nitroacetate (43) in dry toluene gave methyl 3-[3-(5-benzyloxyindolyl)]3-nitrobutanoate (44). Hydrogenation of compound 44 in the presence of Raney nickel and trifluoroacetic acid in ethanol yielded methyl (2RS, 3SR)-2-amino-3-[3-(5-benzyloxyindolyl)] butanoate (45). Hydrogenation of compound 44 in the presence of 10% palladium on charcoal and trifluoroacetic acid in ethanol yielded methyl (2RS, 3SR)-2-amino-3-[3-(5-hydroxyindolyl)] butanoate (46).The structures of the novel compounds were confirmed by 1H NMR, IR, and HRMS or elemental analysis. / Department of Chemistry

The goal of this research project was to synthesize a small library of 3- and 5-arylisoxazoles. These compounds are of interest because of potential biological activity similar to Fipronil. Fipronil is used commercially in the agrochemical industry and exhibits pesticidal activity as a noncompetitive inhibitor of the GABA receptor. By deleting the amino group normally at the 5-position and the cyano group normally at the 3-position and changing the atoms in the heterocyclic ring from containing two nitrogen atoms to one nitrogen and one oxygen atom, we hope to create changes in the binding so the geometry of the GABA receptor may be better understood.The synthesis of our target compounds consisted of many steps. First, brominated intermediates were made from commercially available compounds. The brominated intermediates were converted to aldehydes, which then produced oximes. The oximes were then combined with alkynes through a 1,3-dipolar cycloaddition to form the arylisoxazoles. / Department of Chemistry

Reprint of journal in end pocket / vi, 158 leaves : photos., tables, graphs ; 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 Biochemistry, 1978

Thesis (Ph. D.)--Massachusetts Institute of Technology, 1993. / "February 1993." Includes bibliographical references (p. 215-218).

No description available.

The processes leading to the formation of 2-methyl-2-(methylthio)propanal oxime, known industrially as aldicarb oxime, have been studied. The three stages of the synthesis, viz., chlorination, thiomethylation and oximation have been thoroughly investigated, with the aim of optimising the yield and purity of aldicarb oxime. Attention has been focused on the chlorination step, and the effects of altering various conditions have been determined; the reaction has been carried out in the absence and presence of heat, solvent and buffer, and the extent of chlorine addition has also been varied. These studies have led to some improvement in the yield for this step. Several simple and inexpensive methods for purifying contaminated batches of aldicarb oxime have also been examined. Possible aldicarb oxime contaminants, identified by GLC and GC-MS analysis, have been synthesised for use as chromatographic and spectroscopic standards, and confirmation of the presence of a number of these contaminants has been achieved. Aldehyde trimers have been found to be the primary contaminants present in aldicarb oxime and the thermal stability of these trimers, their corresponding monomers and aldicarb oxime itself has been studied using variable temperature ¹H NMR spectroscopy. Novel pyridine derivatives, with potential as aldicarb analogues, have been synthesised and characterised using spectroscopic methods.

This thesis aims to develop a new and inexpensive synthetic route to the anti-cancer drug etoposide (6) via 4'-demethylpodophyllotoxin (4) or 4'-demethylepipodophyllotoxin (5) involving the oxidative coupling of a dibenzylbutanolide catalyzed by a cell-free extract (CFE) from plant cell culture. This step was studied in depth using the Catharanthus roseus CFE-catalyzed biotransformation of frans-2-(3,5-dimethoxy-4-hydroxybenzyl)-3-(3-hydroxy-4-methoxybenzyl)butanolide (58) to 1-(3,5-dimethoxy-4-hydroxyphenyl)-6-hydroxy-3-hydroxymethyl-7-methoxy-1,2,3,4-tetrahydro-2-naphthoic acid γ lactone (59) as a model. The optimum values of reaction pH, enzyme:substrate ratio and co-factonsubstrate ratio were determined. The butanolide 58 was synthesized by a route involving the Stobbe condensation of 3-benzyloxy-4-methoxybenzaldehyde with dimethylsuccinate to yield 2-(3-benzyloxy-4-methoxybenzylidene)butanedioic acid 1-methyl ester (69). Hydrogenation of 69 to 2-(3-benzyloxy-4-methoxybenzyl)butanedioic acid 1-methyl ester (70) followed by reductive lactonization afforded 3-(3-benzytoxy-4-methoxybenzyl)butanolide (71). Alkylation of 71 with 4-benzyloxy-a-bromo-3,5-dimethoxytoluene (72) gave frans-2-(4-benzyloxy-3,5-dimethoxybenzyl)-3-(3-benzyloxy-4-methoxybenzyl)butanolide (73) which was then converted to the butanolide 58 by catalytic hydrogenolysis. In order to investigate the effect of different aromatic substituents on the oxidative coupling of butanolides, C. roseus CFE-catalyzed biotransformations of frans-2-(3,5-dimethoxy-4-hydroxybenzyl)-3-(3,4-methylenedioxybenzyl)butanolide (74) and frans-2-(3,5-dimethoxy-4-hydroxybenzyl)-3-(3,4-dihydroxy-a-hydroxybenzyl)butanolide (94) were also performed. The biotransformation of 74 gave 2-(3,5-dimethoxy-4-hydroxybenzylidene)-3-(3,4-methylenedioxybenzyl)butanoiide (76) as the sole isolated product. A pathway involving oxidative demethylatton is proposed to account for the balance of the unrecovered material. The butanolide 94, a potential precursor to etoposide, was prepared from piperonal. The lithium anion of 1-bis(phenylthio)methyl-3,4-methylenedioxybenzene (97) and the bromide 72 were added consecutively to but-2-en-4-olide to afford frans-2-(4-benzyloxy-3,5-dimethoxybenzyl)-3-(3,4-methylenedioxy-α,α-bis(phenylthio)benzyl)butanolide (96). A synthetic sequence involving the oxidation of 96 to frans-2-(4-benzyloxy-3,5-dimethoxybenzyl)-3-(3,4-methylenedioxybenzoyl)-butanolide (100), reduction to frans-2-(4-benzyloxy-3,5-dimethoxybenzyl)-3-(α-hydroxy-3,4-methylenedioxybenzyl)butanolide (109) and cleavage of the methylenedioxy and benzyl protecting groups gave the catechol 94. Unfortunately, the CFE-catalyzed oxidation of 94, following treatment with sodium borohydride, yielded 4-(3,4-dihydroxyphenyl)-5,7-dimethoxy-6-hydroxy-2-hydroxymethyl-1,2,3,4-tetrahydro-2-naphthoic acid γ lactone (103) as the sole isolated product. [Formulas omitted] / Science, Faculty of / Chemistry, Department of / Graduate

This thesis is a study of the synthesis of antispasmodics.

by Yiu-bong Leung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 67-68). / Abstract --- p.i / Acknowledgment --- p.ii / Abbreviation --- p.iii / List of spectra --- p.iv / Contents --- p.v / Chapter Part 1: --- A New Synthesis of Rhodium(II) and Iridium(II) Octaethyl- porphyrin Dimers / Chapter 1.1 --- Introduction / Chapter 1.1.1 --- Objective --- p.1 / Chapter 1.1.2 --- Literature Survey --- p.1-7 / Chapter 1.2 --- Result and Discussion --- p.8-10 / Chapter 1.3 --- Conclusion --- p.11 / Chapter Part 2: --- Substituent Effect of meso-pαrα-Arylsubstituted Octabromo- tetraphenylporphyrins / Chapter 2.1 --- Introduction / Chapter 2.1.1 --- Objective --- p.12 / Chapter 2.1.2 --- Literature Survey --- p.12-17 / Chapter 2.2 --- Result and Discussion --- p.18-28 / Chapter 2.3 --- Conclusion --- p.29 / Chapter Part 3: --- "Thermolysis of [2，3，7，8,12,13,17,18-0ctachloro-5,10,15,20- tetrakis(4'-tert-butylphenyl)porphyrinato]-2-phenylethyl- rhodium(III)" / Chapter 3.1 --- Introduction / Chapter 3.1.1 --- Objective --- p.30 / Chapter 3.1.2 --- Literature Survey --- p.30-31 / Chapter 3.2 --- Result and Discussion --- p.32-45 / Chapter 3.3 --- Conclusion --- p.46 / Experimental Section --- p.47-64 / References --- p.65-68 / Spectra --- p.69-83