Chemistry Commons^™

Studies In Peptide Synthesis Towards The Lanthionine Analog Of Des-N-Tetramethyl Triostin A, Ganesh Devdas Kini

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Studies have been carried out towards the synthesis of bicyclic octadidepsipeptide lanthionine 4, an analog of des-N-tetramethyl triostin A. Starting with a symmetrical lanthionine unit 5 (R₁, R₃ = Me; R₂, R₄ = t-butyloxycarbonyl), synthesized from the corresponding cystine by contraction with hexaethylphosphorus triamide, linear octadidepsipeptides 29 and 32 were synthesized.

Attempted cyclizations of 29 and 32 to the bicyclic octapeptide were unsuccessful.

The failure of the symmetrical approach to 4 prompted the synthesis of an unsymmetrical lanthionine unit with appropriate compatible protecting groups. Attempts to synthesize unsymmetrical lanthionines by nucleophilic displacement on …

Studies Toward The Synthesis Of A- And B- Mercapto Alanine Derivatives, And Of A,B- And B, B- Dimercapto Alanine Derivatives, Aldean James Kolar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A convenient, economical, large scale synthesis of N-acetyldehydro-alanine (a-acetamidoacrylic acid) and its methyl ester was developed via a sequence of N-chlorination-dehydrochlorination. The method was extended to the synthesis of the corresponding N-benzoyl, N-phenylacetyl and N-benzyloxycarbonyl derivatives.

The conversion of a-methoxy-N-acetyl alanine derivatives to the corresponding a-mercapto alanine derivatives, using zinc chloride and an appropriate mercaptan, was investigated. Methyl a-methoxy-N-acetyl-D, L-alaninate was successfully converted to the a-acetylthio derivative, in 24% yield; however, a 90% yield could be obtained by treatment of the dehydroalanine derivative with hydrogen chloride gas in neat thiolacetic acid.

A facile conversion of the a-acetylthio derivative to the …

Mechanism Of Phenyl Azide-1,2-Cyclonoadiene Adduct Formation And Isomerization Of This Adduct, Isom Harrison

University of the Pacific Theses and Dissertations

A major purpose of this research was to investigate the mechanism of aryl azide addition to allenes. Much evidence has accumulated in support of a concerted mechanism for aryl azide additions to simple alkenes. Consistent with these findings, this addition is a symmetry allowed process. The analagous aryl azide additions to allenes have received little mechanistic study. The approach taken in this work was to probe the mechanism by using optically active 1,2-cyclonanadiene, observing the stereochemistry of the adduct formed upon addition of phenyl azide.

Another goal was to investigate the isomerization of the phenyl azide-1,2-cylononadiene adduct, 10-phenyl-10,11,12-triaza-△ 11 -bicyclo …

The Synthetic Chemistry Of Carboxyalkyl-P, P-Diphenyl Phosphines, Larry S. Andrews

Chemistry Honors Papers

This 55 page thesis examines the preparation of carboxyalkyl-P and P-diphenyl phosphines to determine their acidity characteristics as a function of structure and to characterize their ability to function as chelating agents.

Synthesis And Characterization Of Some Dioxane Complexes, James Donald Satterlee

All Master's Theses

The boron trifluoride, tin (IV) fluoride and titanium (IV) fluoride complexes with 1,4-dioxane have been prepared and studied using infrared techniques. The compositions of the complexes have been determined and correspond to the 1:1 adducts in the case of the tin and titanium compounds. The boron trifluoride adduct is a 2:1 (acid:base) adduct. Infrared spectra in the region 1300 cm.-1 to 550 cm.-1 are given and the effects of coordination upon the ligand vibrations are described.

I. Studies Toward The Synthesis Of Echinodithianic Acid And Ii. The Temperature Dependent Nmr Spectrum Of Methyl N-Acetylsarcosinate, Alan Leroy Love

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Approaches to the preparation of echinodithianic acid (5) from 2,5-dicarbomethoxy-1,4-dithiane (1) were not successful, due to the inability to carboxylate or carboalkoxylate 1 at carbons 2 and 5. Studies toward the synthesis of 5 utilizing methyl 2-acetamidoacrylate (8) have been investigated. The electrophilic addition of sulfur dichloride to 8 yielded bis-(2-acetamido-2-carbo-methoxyvin-1-yl) sulfide, while the addition of thiocyanogen chloride to 8 produced methyl 2-acetamido-3-thiocyanato-acrylate.

As electrophilic additions of unsymmetrical dipolar reagents to methyl 2-acetamidoacrylate (8) are not reported in the literature, the addition of hydrogen bromide to 8 was studied to determine the orientation effect of the acetamido group.

Methyl 2-acetamido-2-bromopropionate …

The Synthesis And Reactions Of Isatoic P-Linear Bis Anhydride, Willis G. Frick

Chemistry Honors Papers

This 41 page thesis examines methods of synthesizing isatoic anhydrides.

The Synthesis Of 2-Carboxyethyl-P, P-Diphenylphosphine And A Study Of It As A Potential Chelating Agent, Harriet V. Taylor

Chemistry Honors Papers

This 24 page thesis examines the synthesis of organo-phosphorous acids and their stability as ligands.

The Synthesis And Reactions Of 8-Carboxy Isatoic Anhydride, James E. Scheirer

Chemistry Honors Papers

This 34 page thesis examines the preparation and characterization of 8-carboxy isatoic anhydride and the study of its reactions, leading to the synthesis of compounds of new composition.

The Synthesis And Reactions Of 6-Carboxy Isatoic Anhydride, Jacqueline I. Kroschwitz

Chemistry Honors Papers

This 27 page thesis researches the preparation and characterization of 6-carboxy isatoic anhydride and the study of the reactions of this compound, leading to the synthesis of a series of compounds of new composition.

The Synthesis And Reactions Of 7-Carboxy Isatoic Anhydride, Elsa M. Janle

Chemistry Honors Papers

This 16 page thesis examines the preparation and characterization of 7-carboxy isatoic anhydride and the study of the reactions of this compound of new composition.

Cyclization Of W-Tertiary Butyl Uramido Benzoic Acid, John R. Lovett

Chemistry Honors Papers

This 13 page thesis investigates the cyclization of w-tertiary butyl uramido benaoic acid and establishes the equation for the resulting reaction.

Experiments On The Keto-Cleavage Of D1 (2-Cyanoethyl) Acetoacetic Ester, Charles W. Huff

Chemistry Honors Papers

This 12 page thesis examines effects of the addition of acrylo-nitrile to acetoacetic ester.