Thesis (Ph. D.)--University of Nebraska, 1936. / eContent provider-neutral record in process. Description based on print version record. Bibliography: p. 41.

Thesis (Ph. D.)--University of Nebraska, 1936. / eContent provider-neutral record in process. Description based on print version record. Bibliography: p. 41.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 73-76).

Th.--Sci.--Toulouse--I.N.P., 1980. N°: 45.

Highly polar organic fluorinated motifs are of interest in materials chemistry, for example, in liquid crystal applications. Cyclohexane is an important and widely used structural motif within organic chemistry. Work has been carried out to prepare single stereoisomers of multivicinal fluorinated cyclohexanes, a class of compounds that has not been previously produced. A synthesis of the all-syn-1,2,3,4-tetrafluorocyclohexane, in 9 steps from cyclohexa-1,3-diene will be presented. The ¹⁹F NMR spectra of the all-syn-1,2,3,4-tetrafluorocyclohexane shows interesting dynamic conformational effects. This is a small polar organic molecule, which was crystalline at room temperature. The structure of the compound was confirmed by single crystal X-ray diffraction studies. The synthesis of the all-syn-1,2,4,5-tetrafluorocyclohexane from cyclohexa-1,4-diene is also presented. The synthesis of a single diastereoisomer of 1,2,3,4,5,6-hexafluorocyclohexane, derived from benzene in 5 steps, is presented. As with the tetrafluoro compounds, the ¹⁹F NMR spectra of this compound shows dynamic conformational effects. The structure of the compound was confirmed by single crystal X-ray diffraction studies. The 1,2,4,5-tetrafluorocyclohexane motif was elaborated to contain a phenyl group, producing “rod-like” molecules. This motif was synthesised in view of potential applications for liquid crystalline materials.

This thesis describes the preparation of 5-chloro-2-trimethyl-stannyl-1-pentene (111) and its conversion into 5-chloro-2-lithio-1-pentene (112). The latter reagent, which reacts smoothly with cyclohex-anone at -78°C to give 5-chloro-2-(1-hydroxycyclohexyl)-1-pentene (132), was found to be thermally unstable at temperatures higher than -63°C. Reagent (112) was transformed into the Grignard reagent (144) and the organocopper-phosphine complex reagent (145). Conjugate addition of reagents (144) and/or (145) to cyclic enones under appropriate conditions followed by cyclization of the resultant products, effected useful methylenecyclohexane annulation sequences [(104) → (116)]. This methylenecyclohexane annulation method served as one of the two key steps in the syntheses of (±)-axamide-1 (174), (±)-axiso-nitrile-1 (173), and the corresponding C-10 epimers. Thus, copper(I)-catalyzed addition of the Grignard reagent (144) to 2-methyl-2-cyclo-penten-1-one (152), followed by cyclization of the resultant chloro ketone (159), gave the annulation product (170), which was converted into the enone (203). The other key step in the projected synthesis, which involved TiC1₄-catalyzed conjugate addition of the bis(trimethyl-silyl) ketene acetal (226) to the enone (203), provided a mixture of the keto acids (222) and (223). With appropriate functional group manipulations, (222) was converted into (±)-axamide-1 (174) and (±)-axisonitrile (173), while (223) was converted into (±)-10-epi-axamide-1 (224) and (±)-10-epi-axisonitrile-1 (225). [Formula Omitted] / Science, Faculty of / Chemistry, Department of / Graduate

by Eric Kwok Wai Tam. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references. / Table of Contents --- p.i / Acknowledgement --- p.iv / Abstract --- p.v / Abbreviation --- p.vii / Part A / Enantiospecific Syntheses of Cyclohexane Oxides from (-)-Quinic Acid / Chapter 1. --- Synthetic Application of (-)-Quinic Acid --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Syntheses of Cyclohexane Derivatives --- p.2 / Chapter 1.2.1 --- Syntheses of Shikimic Acid (2) and its Derivatives --- p.2 / Chapter 1.2.2 --- "Syntheses of D-myo-Inositol 1,4,5-Trisphosphate (52) & its analog" --- p.15 / Chapter 1.2.3 --- Syntheses of Mycosporins --- p.17 / Chapter 1.2.4 --- Synthesis of (+)-Palitantin (76) --- p.19 / Chapter 1.2.5 --- "Synthesis of 2-Crotonyloxy-(4R,5R,6R)-4,5,6-trihydroxy- cyclohex-2-enone (COTC) (82)" --- p.20 / Chapter 1.2.6 --- Syntheses of Cyclophellitol (83) and its Diastereomers --- p.21 / Chapter 1.2.7 --- Syntheses of Pseudo-sugars and its Derivatives --- p.24 / Chapter 1.2.8 --- Syntheses of Aminocyclitol Antibiotics --- p.34 / Chapter 1.2.9 --- Syntheses of A-ring Precursor of Daunomycin --- p.36 / Chapter 1.2.10 --- "Synthesis of 19-nor-lα,25-Dihydroxyvitamin D3" --- p.38 / Chapter 1.2.11 --- Synthesis of Isoquinuclidines --- p.41 / Chapter 1.2.12 --- Synthesis of Cyclohexenyl Iodide: Taxol CD-ring Precursor --- p.44 / Chapter 1.2.13 --- Synthesis of C-20 to C-34 Segment of FK-506 --- p.46 / Chapter 1.2.14 --- Synthesis of the Hexahydrobenzofuran Subunit of Avermectins --- p.49 / Chapter 1.2.15 --- Synthesis of Bicyclic Core of Enediyne --- p.50 / Chapter 1.2.16 --- Syntheses of Two Enantiopure Derivatives of 4-Hydroxy-2-cyclohexone --- p.53 / Chapter 1.3 --- Synthesis of Homochiral Linear Molecules --- p.57 / Chapter 1.3.1 --- Syntheses of (3S)-Mevalonolactone and its Derivatives --- p.57 / Chapter 1.3.2 --- Synthesis of the Subunit in Maytansinoids --- p.58 / Chapter 1.3.3 --- Synthesis of (+)-Negamycin --- p.59 / Chapter 1.3.4 --- Syntheses of Hepoxilins B3 and its Stereoisomers --- p.61 / Chapter 1.3.5 --- Synthesis of C-21 to C-25 Fragment of FK-506 --- p.62 / Chapter 1.4 --- Synthesis of Cyclopentane Derivatives --- p.63 / Chapter 1.4.1 --- Synthesis of 11 α-Hydroxy-13-oxaprostanoic Acid --- p.65 / Chapter 1.4.2 --- Synthesis of (-)-Pentenomycin I --- p.66 / Chapter 1.4.3 --- Syntheses of Carbovir and its Derivatives --- p.66 / Chapter 1.5 --- Synthesis of Cycloheptane Derivatives --- p.68 / Chapter 1.6 --- Conclusion --- p.70 / References --- p.71 / Chapter 2. --- Introduction of Cyclohexane Oxides --- p.81 / Chapter 2.1 --- General Background --- p.81 / Chapter 2.2 --- Previous Syntheses of Cyclohexane Oxides --- p.86 / Chapter 2.2.1 --- Racemic Syntheses of Crotepoxide --- p.86 / Chapter 2.2.2 --- Racemic Syntheses of Senepoxide --- p.89 / Chapter 2.2.3 --- A Racemic Synthesis of Pipoxide --- p.92 / Chapter 2.2.4 --- Syntheses of Enantiopure Cyclohexane Oxides --- p.93 / References --- p.96 / Chapter 3. --- Retrosynthetic Analysis and Strategy --- p.99 / Chapter 3.1 --- Antithetic Analysis of Cyclohexane Oxides --- p.99 / Chapter 3.2 --- Problems Encounter in the Conversion of Diene into Cyclohexane Oxides --- p.100 / Chapter 3.3 --- Photo-oxygenation Approach to Cyclohexane Oxides --- p.102 / Chapter 3.4 --- Reasons for Choosing the Silyl Ether as Blocking Group --- p.104 / Chapter 3.5 --- Strategy for Synthesis of Diene 373 from Quinic acid --- p.105 / References --- p.106 / Chapter 4. --- Results and discussion --- p.108 / Chapter 4.1 --- Synthesis of Silyl Benzoate381 --- p.108 / Chapter 4.2 --- Synthesis of Alkene373 --- p.111 / Chapter 4.3 --- Syntheses of (+)-Crotepoxide (289)，(+)-Bosenepoxide (290) and (-)-iso-Crotepoxide (304) --- p.115 / Chapter 4.4 --- "Syntheses of the (+)-β-Senepoxide (295)，(+)-Pipoxide Acetate (365), (-) Tintanoxide (294) and (-)-Senepoxide (291)" --- p.121 / References --- p.124 / Chapter 5. --- Conclusion --- p.126 / Chapter 6. --- Experimental Section --- p.128 / References --- p.142 / Part B / Ruthenium Catalyzed cis-Dihydroxylation of Alkene / Chapter 1. --- Introduction --- p.143 / Chapter 1.1 --- Background --- p.143 / Chapter 1.2 --- General cis-Dihydroxylation Methods --- p.144 / Chapter 1.2.1 --- Potassium Permanganate (KMnO4) --- p.144 / Chapter 1.2.2 --- Osmium Tetraoxide (OsO4) --- p.146 / Chapter 1.3 --- Ruthenium Tetraoxide Oxidations --- p.148 / Chapter 1.4 --- Previous Reports of Using Ruthenium Tetraoxide (RuO4) Mediated syn-Dihydroxylation of Olefins --- p.149 / Chapter 1.4.1 --- The Snatzke and Fehlhaber Work --- p.149 / Chapter 1.4.2 --- The Sharpless and Akashi Work --- p.150 / Chapter 1.4.3 --- The Sica and Co-workers Work --- p.150 / References --- p.152 / Chapter 2. --- Ruthenium-Catalyzed cis-Dihydroxylation of Alkenes --- p.155 / Chapter 2.1 --- """Flash"" Dihydroxylation" --- p.155 / Chapter 2.2 --- "Stereochemical Outcome of ""Flash"" Dihydroxylation" --- p.155 / References --- p.157 / Chapter 3. --- Results and Discussion --- p.158 / Chapter 3.1 --- "Scope and Limitations of ""Flash"" Dihydroxylation" --- p.158 / Chapter 3.2 --- "Study of the Diastereoselectivity of ""Flash"" Dihydroxylation" --- p.168 / Chapter 3.3 --- "Study of Co-oxidants for ""Flash"" Dihydroxylation" --- p.170 / Chapter 3.4 --- "Solvent Effect for ""Flash"" Dihydroxylation" --- p.171 / Chapter 3.5 --- "Synthetic Application of ""Flash"" Dihydroxylation" --- p.173 / References --- p.175 / Chapter 4. --- Conclusion --- p.176 / Chapter 5. --- Experimental Section --- p.177 / References --- p.185 / Appendix --- p.186

No description available.

Reflection-absorption infrared spectroscopy (RAIRS) has been used to probe the interaction of cyclohexane, partially deuterated cyclohexane C₆HD₁₁, toluene and ethylene with the Ni{111} surface. The coadsorption of cyclohexane and oxygen on the Ni{111} surface has also been studied in some detail; the effects of differing coverages of both pre- and post- dosed oxygen on cyclohexane adsorption has been investigated. As these experiments were the first to be completed using a new UHV system, an important element of this PhD project involved commissioning the UHV system, including the LEED and Auger apparatus, and setting up the RAIRS optical system. On the clean Ni{111} surface at 110 K adsorbed cyclohexane exhibits a site symmetry of C_3v which persists through to the multilayer regime. Adsorbed molecules in the first layer exhibit a broadened and downshifted vCh stretching vibrational band, thought to arise from CH...M interactions and observed on many metal single crystal surfaces. The effect of coadsorbed oxygen on cyclohexane adsorption is strongly coverage dependent. At lower oxygen coverages, θ_O ≤ 0.25, a further downshifting of the softened vCH stretching vibration is observed, indicating the importance of charge transfer from the filled CHσ orbital to the metal in weakening the C-H bond. Adsorption of cyclohexane on the Ni{111}-(√3x√3)R30°-O surface, θ_O = 0.33, leads to total suppression of any C-H...M interaction, attributed to blocking of the bare metal sites by the adsorbed atoms. Post-dosing of oxygen on the cyclohexane adlayer leads to compression of existing islands of cyclohexane, involving molecular transfer from the first layer to the second. This is attributed to the difference in heats of adsorption of the two adsorbates.

No description available.