by Yun Yang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 111-118). / Acknowledgements --- p.i / Contents --- p.ii / Abstract --- p.v / List of Acronyms and Abbreviations --- p.vi / Chapter Chapter 1. --- Introduction / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Reactions of Furans / Chapter 1.2.1 --- Electrophilic Substitution --- p.3 / Chapter 1.2.2 --- Nucleophilic Substitution --- p.6 / Chapter 1.2.3 --- Addition Reaction --- p.9 / Chapter 1.2.4 --- Oxidation Reaction --- p.9 / Chapter 1.3 --- Review of Synthetic Methods for the Syntheses of Polysubstitued Furans --- p.11 / Chapter 1.3.1 --- "From 1,4-Dicarbonyl Compounds" --- p.11 / Chapter 1.3.2 --- From α-Haloketones --- p.12 / Chapter 1.3.3 --- From Hetero Diels-Alder and Retro-Diels-Alder Reactions --- p.15 / Chapter 1.3.4 --- From Alkynes / Chapter 1.3.4.1 --- Via Radical Cyclization --- p.16 / Chapter 1.3.4.2 --- Via Insertion of Isocyanides --- p.16 / Chapter 1.3.4.3 --- Via Addition of Carbenoids --- p.17 / Chapter 1.3.4.4 --- Via Pd-Catalyzed Addition and Cyclization Reactions --- p.19 / Chapter 1.3.5 --- FromAllenes / Chapter 1.3.5.1 --- Via Allenic Sulfonium Salts --- p.20 / Chapter 1.3.5.2 --- Via Rh or Ag Catalyzed Cyclization --- p.21 / Chapter 1.3.5.3 --- Via Acylium Ions Addition to Allenylsilanes --- p.21 / Chapter 1.3.5.4 --- Via Allenic Palladium Intermediates --- p.22 / Chapter 1.3.6 --- From Pyrylium Salts --- p.23 / Chapter 1.3.7 --- From Miscellaneous Sources --- p.24 / Chapter 1.4 --- "Review of Synthetic Methods for the Syntheses of 3,4-Disubstituted Furans" / Chapter 1.4.1 --- From Functionalization of Furan Ring --- p.25 / Chapter 1.4.1.1 --- "Modification of Diethyl Furan-3,4-dicarboxylate" --- p.25 / Chapter 1.4.1.2 --- Modification of 3-(Hydroxymethyl)furan --- p.27 / Chapter 1.4.1.3 --- "From Boroxines Derived from 3,4-Bis(trimethylsilyl)furan…" --- p.28 / Chapter 1.4.2 --- From Ylide --- p.29 / Chapter 1.4.3 --- "From 2-Butyne-l,4-diol" --- p.29 / Chapter 1.4.4 --- From Hetero Diels-Alder and Retro-Diels-Alder Reactions --- p.30 / Chapter 1.4.5 --- From Sulfolene --- p.31 / Chapter 1.5 --- Aim of the Present Work --- p.32 / Chapter Chapter 2. --- Results and Discussion / Chapter 2.1 --- "Synthesis of 3,4-Bis(tri-n-butylstannyl)furan (47) and 3-(Tri-n-butylstannyl)furan (48) from Bis(tri-n-butylstannyl)acetylene (49) and 4-Phenyloxazole (50)" --- p.34 / Chapter 2.2 --- Stille-type Palladium-catalyzed Cross-coupling Reactions with Various Organic Halides --- p.36 / Chapter 2.2.1 --- General Features of Stille's Reaction --- p.38 / Chapter 2.2.2 --- Solvents and Catalysts --- p.42 / Chapter 2.2.3 --- Isolation and Purification of Products --- p.45 / Chapter 2.2.4 --- Direct Coupling with Organic Halides --- p.45 / Chapter 2.2.4.1 --- Acid Chloride --- p.46 / Chapter 2.2.4.2 --- Aryl Halide --- p.51 / Chapter 2.2.4.3 --- Vinyl Halide --- p.53 / Chapter 2.2.4.4 --- Allylic Bromide --- p.53 / Chapter 2.2.4.5 --- Benzylic Halide --- p.54 / Chapter 2.2.5 --- Mechanistic Aspects / Chapter 2.2.5.1 --- Mechanism for the Stille's Reaction of Acid Chloride --- p.54 / Chapter 2.2.5.2 --- Mechanism for the Stille's Reaction of Aryl Halide --- p.56 / Chapter 2.2.6 --- Carbonylative Coupling --- p.59 / Chapter 2.2.7 --- Conclusion --- p.64 / Chapter 2.3 --- "Synthesis of Unsymmetrical 3,4-Disubstituted Furans via Lithiation of 3,4-Bis(tri-n-butylstannyl)furan (47)" / Chapter 2.3.1 --- Lithiation of Organotin Compounds: General Remarks --- p.65 / Chapter 2.3.2 --- "Lithiation of 3,4-Bis(tri-n-butylstannyl)furan (47) with n-BuLi" --- p.68 / Chapter 2.3.3 --- Trapping of 3-Lithium-4-(tri-n-butylstannyl)furan (63) with Electrophiles --- p.70 / Chapter 2.3.4 --- "Synthesis of Unsymmetrical 3,4-Disubstituted Furans from 3-Substituted-4-(tri-n-butylstannyl)furan (64) via Stille's Reactions" --- p.72 / Chapter 2.3.5 --- Conclusion --- p.75 / Chapter 2.4 --- Halogenation --- p.75 / Chapter Chapter 3. --- Application to Natural Product Synthesis / Chapter 3.1 --- "Synthesis of a Key Intermediate in the Total Synthesis of (20,S)-Camptothecin" --- p.79 / Chapter 3.2 --- Synthesis of an Analog of Lactaral --- p.80 / Experimental --- p.83 / References --- p.111 / Appendix --- p.119

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE / Vita. / Includes bibliographical references. / by Catherine Ann Seymour. / Ph.D.

Inoculation trials were set up in fumigated nursery beds for red alder (Alnus rubra Bong.) seedling production. Frankia inoculum was applied in eight treatments: control, nodule suspension, and three levels of cell suspension (strain ArI5) applied with and without a peat carrier. Seedlings were evaluated at midseason and lifting. The peat inoculum treatment produced larger seedlings than the other treatments, both at mid-season and at lifting. The other treatments had little effect on growth. Size differences paralleled differences in degree of nodulation. Differences in percentage of seedlings nodulated were most pronounced at midseason, indicating that the inoculation conferred primarily an early-season advantage. In a second nursery experiment, Frankia inoculum was applied in a peat mix carrier, in four treatments: uninoculated control, strain ArI5, strain AvcI1, and combined dual-inoculum. Seedlings were evaluated at midseason and at lifting. Frankia DNA from nodules was analyzed by DNA fingerprinting. The controls were poorly nodulated and grew slowly. The single strain inoculum for ArI5 produced larger seedlings than for AvcI1, both at mid-season and at lifting. The dual-inoculum treatment produced larger seedlings than all other treatments. The AvcI1 single-inoculum nodules primarily produced fingerprints identical to AvcI1, but nodule fingerprints from all other treatments were dominated by ArI5 patterns. In a field experiment, nodulation capacity was determined for soils from red alder stands in the Oregon coast range covering a wide span of ages. Total nitrogen, total carbon, nitrate, ammonium and pH were measured on the same soil samples. Soil pH was most highly correlated with nodulation potential, with nitrate content also significant. Cluster analysis of the sites using these two variables produced two groups with distinctly different nodulation capacities. The higher capacity cluster was lower in nitrate and higher in pH than the majority of sites in the lower capacity cluster. There was general overlap in the age ranges for the two groups but the lower capacity cluster contained the oldest sites. / Graduation date: 2002

No description available.

Paderborn, University, Fachb. Chemie u. Chemietechnik, Diss. 1990.

Thesis (M. Phil.)--University of Hong Kong, 1987.

Poly(ADP-ribose) polymerase (PARP) represents a large family of enzymes that are activated upon DNA breakage, which are then involved in a cascade of reactions that eventually lead to cell death. PARPs, known to cause a variety of damage to the human body, are targets of many researches’ investigating potential inhibition mechanisms. To this point, plenty of PARP inhibitors have been synthesized and tested for potency against many diseases. Some have great potency against particular diseases, while others are already being used as drugs. The current research suggests a potential synthesis of novel PARP inhibitors, to be accomplished through Diels-Alder chemistry. The proposed compounds consist of an isoindolinone core bearing different functional groups. Three different strategies are described for the synthesis of the novel PARP inhibitors and all protocols involve sulfur dioxide extrusion chemistry to create a diene, the desired transient starting material. The diene is envisioned further to be reacted with a variety of dienophiles to give possibly potential PARP inhibitors. / NSERC

No description available.

No description available.

The synthesis of methyl 3,6-dimethylpyridine-2-carboxylate (192) by the Diels-Alder addition of 3-butene-2-one dimethylhydrazone (190) and methyl-2-butynoate (16) is described. The structure of 192 was confirmed by the synthesis of methyl 2,6-dimethylpyridine-3-carboxylate (195), the opposite regioisomer.The synthesis of methyl 3,5-dimethylpyridine-2-carboxylate (199) from [4+2] cycloaddition of 2-methyl-2-propenal dimethylhydrazone (171) and 16 is described. In addition to producing a small amount of 199 directly, the reaction produced an intermediate of possible structure 198 which yielded 199 on catalytic dehydrogenation.On prolonged heating, 2-acetyl-5-methylpyridine (200) was produced by the reaction of diene 171 with methyl vinyl ketone (176).The preparation of 2-cyan-5-methylpyridine (201) from the tetrahydropyridine derivative 175 via catalytic dehydrogenation is described.The synthesis of 5,7-dioxo-3-methyl-6-phenyl-1,1.,5,6,7-pentahydropyrroloC3,1.-b] pyridine (202) through the Diels-Alder addition of diene 171 and N-phenylmaleimide (149) is described. Also reported is the preparation of 5,7-dioxo-3-methyl-6-phenyl-3,5,6-trihydropyrrolo [3,1+-b]pyridine (203) via dehydrogenation of 202. / Department of Chemistry