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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The relation of structure, affinity and reactivity of ketones

Carswell, Harry Eaton. January 1927 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1927. / Typescript. With this is bound: The relation of the structure of ketones to their reactivity and affinity in acetal formation / By Harry E. Carswell and Homer Adkins. Reprinted from Journal of the American Chemical Society, vol. 50 (1928), p. 235-241.
12

Studies in steroid ketones

Anchel, Marjorie Wolff, January 1938 (has links)
Thesis (Ph. D.)--Columbia University, 1939. / Vita. Consists of three articles, the second and third reprinted from the Journal of biological chemistry, v. 124 and 125, 1938. Bibliography: p. 8, 11, 19-20.
13

Hydration of ketones in mixtures of water and dipolar aprotic solvents

Van Dyke, John D. January 1970 (has links)
The hydration of a series of α,α,α-trifluoroacetophenones has been studied in sulfolane-water and dimethyl sulfoxide-water solvent systems and their extents of hydration measured by ¹⁹F N.M.R. spectroscopy and U.V. spectroscopy. In order to quantitatively determine the equilibrium constants for the very readily hydrated ketones in this series and at the same time to study the effect of a dipolar aprotic solvent on the ability of an aqueous medium to hydrate a ketone, a function W₀ (analogous to the Hammett acidity function H₀) was developed for the systems sulfolane-water and dimethyl sulfoxide-water. Nine substituted α,α,α -trifluoroacetophenones were used to establish the W₀ scale for sulfolane-water; two were used to establish the scale for dimethyl sulfoxide-water. The ability of a medium to reduce the extent of ketone hydration is indicated by an increase in the medium's W₀ function. In sulfolane-water, W₀ values increase continuously as sulfolane is added to the medium, ranging from 0 in pure water to about 2.7 in 99 mole % sulfolane. The corresponding function in dimethyl sulfoxide-water decreases initially as dimethyl sulfoxide (DMSO) is added reaching a minimum of -0.42 at 40 mole % DMSO. As more DMSO is added, the function rises and reaches a value of about 1.1 in 99 mole % DMSO. The differences between the W₀ functions in DMSO and sulfolane are accounted for by differences in the behavior of the water activity terms and the activity coefficients of the ketone hydrates in the two solvent systems. From considerations of the effect of the dipolar aprotic solvents on the hydrate molecules, it appears that the activity coefficients of the hydrates are affected in the same manner as the activity coefficients of water but to a greater degree. Data on the hydration of s-dichloroacetone in dioxane-water and acetonitrile-water (supplied by Professor R.P. Bell) allowed the development of functions in these solvents. A comparison of W₀ functions shows the following order for effectiveness of a solvent in decreasing the extent of hydration: sulfolane > acetonitrile > dioxane > DMSO. The pK[subscript d] (d = dehydration) values for the nine substituted α,α,α -trifluoroacetophenones determined in sulfolane-water vary from -0.86 for the 4-dimethylamino derivative to 3.15 for the 3-nitro derivative. A plot of log K[subscript d] versus the Hammett substituent constants (ϭ⁺) for these compounds yields a ρ⁺value of -1.62. Measurements of the kinetics of hydration in sulfolane-water mixtures containing no acid indicate that three water molecules are intimately associated with the hydrating ketone in the transition state for the water-catalyzed mechanism. In sulfolane-water mixtures containing acid, the same measurements do not indicate conclusively the number of water molecules associated with the transition state. The heats of reaction (ΔH) and entropies of reaction (ΔS) for the dehydration of α,α,α -trifluoroacetophenone hydrate and its 4-methoxy derivative were determined in sulfolane-water mixtures. ΔH values range between 7 and 10 kcal/mole and ΔS values between 19 and 25 e.u. Changes in solvent composition and ketone structure appear to have relatively little effect on ΔH and ΔS. / Science, Faculty of / Chemistry, Department of / Graduate
14

Diastereoselective cyclopropanations of alpha,beta-unsaturated ketals derived from chiral hydrobenzoin

Torok, Daniel Seth, 1963- January 1988 (has links)
2-Cycloalken-1-one-(-)-erythro-hydrobenzoin ketals undergo efficient and diastereoselective cyclopropanation when treated with an excess of Simmons-Smith reagent. The resulting crystalline products yield enantiomerically pure cyclopropyl compounds upon recrystallization. For example, 2-cyclohexen-1-one-(-)-erythro-hydrobenzoin ketal gave, in 90% yield, a 19:1 mixture of diastereomeric cyclopropanes as established by 62.9 MHz ¹³C NMR spectroscopy. Upon one recrystallization, diastereomerically pure cyclopropane was obtained in 78% recovery. Hydrolysis gave (+)-norcaranone of greater than 99% ee. Three other examples are presented which demonstrate the advantages of hydrobenzoin ketals over previously used homochiral ketals, as well as several techniques for the synthesis of chiral hydrobenzoin.
15

Synthetic applications of alkylidene carbenes

Walker, Louise F. January 1998 (has links)
No description available.
16

Studies towards the synthesis of the squalestatins

Masters, Susannah Jane January 1999 (has links)
No description available.
17

The metabolism of ketone bodies in the baboon leucocyte

Weight, M. J. 02 July 2014 (has links)
Thesis (M.Sc.)--University of the Witwatersrand, Faculty of Science, 1968.
18

Complementary approaches to 2,2-disubstituted 1,4-diketones, and the preparation and properties of 3H- and 3H-pyrroles derived from them /

Lui, Kon-hung. January 1988 (has links)
Thesis (Ph. D.)--University of Hong Kong, 1988.
19

The electronic structure and spectroscopy of diarylidene-cycloalkanones and their protonated cations

Ucak-Astarlioglu, Mine Gunes. January 2003 (has links)
Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: polyene ketones; diarylidene-cycloalkanones; spectroscopy; electronic structure; protonated cations; photochemistry; electronic states. Includes bibliographical references (p. 189-191).
20

Complementary approaches to 2,2-disubstituted 1,4-diketones, and the preparation and properties of 3H- and 3H-pyrroles derived from them

呂幹雄, Lui, Kon-hung. January 1988 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

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