Thesis (Ph. D.)--University of Chicago, 1934. / Lithoprinted. "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois."

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A series of C-stannylated monosaccharide derivatives were prepared and their chemistry studied. Derivatives having a hydroxyl group ? to tin, i.e. methyl 4,6-0- benzylidene-2(3)-deoxy-2(3)-triphenylstannyl-?-D-allopyranosides [(1) and (2)] and 6-deoxy-l,2-0-isopropylidene-6-triorganostannyl-?-D-glucofuranose (3, R=Me, 4, R=Ph) were prepared by reaction of appropriate triorgano-tin-lithiums with epoxy sugars. Reactions of 3 with TFA, acetyl chloride, benzoyl chloride, ethyl chloroformate, sulphur dioxide and TCNE produced via elimination, 5,-6- dideoxy-1,2-0-isopropylidene-?-D-xylo-hex-5-enofuranose (15). Methyl-tin bond cleavage in 3, with formation of C-(dimethylhalogenostannyl)- monosaccharides, occurred on reaction with I2, Br2 or Pd(COD)Cl2. The product from the I2 reaction was unstable in solution and gave the elimination product 15. MeLi gave no reaction, and both SnCl4 and ClSO3H gave Me3SnCl and acetone as the only recognisable products. The triphenylstannyl derivatives 1, 2 and 4 underwent phenyl-tin cleavage with electrophiles. The 1,2:5,6-di-0-isopropylidene-3-C-(triorganostannyl)methyl-?-D-allofuranoses [R=Me, (11), Bu (12) or Ph (13)] were prepared by reaction of an appropriate (triorganostannyl)methy1-lithium with a keto-sugar. Substitution to form the C-(iodostannylated) monosaccharide occurred for all compounds on reaction with iodine. No elimination was obtained on reaction of 11 with TFA, deprotection being the predominant route. The elimination product was isolated from the attempted Pd-catalysed coupling of 12 with PhCOCl and from reaction of the methoxymethyl ether derivative 14 (R=Ph) with PhLi. No reaction was observed on treatment of 12 and 13 with organolithium reagents. Derivatives having a hydroxyl group ? to tin, the l,2:5,6-di-0- isopropylidene-3-C-triorganostannyl-?-D-allofuranoses [R=Me (9) and Ph (10)] were prepared via reaction of a triorganostanny1-lithium with a keto- sugar. Compound 9 gave predominant methyltin cleavage with I2, was partially deprotected by TFA and gave the methyl-coupled product, Me-R, on reaction with carbon electrophiles, R-Y, under Pd-catalysis. The triphenyltin derivative 10, decomposed on treatment with TFA, gave no reaction with phenyl-lithium and pheny1-tin cleavage with I2. The ?-alkoxy derivatives, l,2:5,6-di-0-isopropylidene-3-0-(triorgano-stannyl)methyl-?-D-glucofuranose [R=Me (5) and Ph (6)] and (triorgano-stannyl)methyl 2,3:5,6-di-O-isopropylidene-?-D-mannofuranoside [R=Me (7) and Ph(8)] were prepared via alkylation of a free hydroxyl by iodomethyl-triorganostannane. The triphenyl derivatives underwent pheny1-tin cleavage with I2 and TFA, while tin-lithium exchange occurred with PhLi to give a lithiated sugar which was trapped by a variety of reagents. Compounds 5 and 7 gave competitive cleavage of Me-Sn and R*OCH2-Sn bonds on treatment with halogens. Reaction with TFA, acetyl chloride and SO2 gave predominant reaction at the protecting groups and no reaction was observed for benzoyl chloride and ethylchlorofornate. Tin(IV) chloride gave mainly methyl transfer to tin to form MeSnCl3 and the C-chlorodimethylstannyl derivatives. Treatment with Pd(COD)Cl2 however, gave competitive transfer of methyl group and sugar moiety from tin to palladium. The crystal structures of 10, 13 and the iodo-derivative of 12 were determined; and the results of biological testing of 10 and 13 for antitumour activity and 1, 6 and 8 for plant protection properties are reported.

Bibliography: leaves [89-92]

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Thesis (M.Sc.) -- University of Adelaide, Dept. of Chemistry, 2001. / Bibliography: leaves [89-92].

A summary of the tin hydride method of generating radicals in organic synthesis is presented, followed by illustrative examples of other methods available for mediating radical reactions, with a particular emphasis on recent developments. This is followed by four chapters describing our efforts to introduce alternative methods for generating radicals. A range of l-alkylcyclohexa-2,5-diene-l-carboxylic acids have been prepared by Birch reduction-alkylation methodology and shown to generate the corresponding alkyl radical by thermal initiation with dibenzoyl peroxide. The 1-benzyl, cyclopentyl and t-butyl precursors (17,15, and 16 respectively), acted as sources of radicals which were trapped with cyclohexenone to give the corresponding 3-alkylcyclohexanone adducts in yields of 52%, 30% and 25% respectively. Addition products were also observed when acrylonitrile and vinyl benzoate were employed as the radical traps. 1-[2-(Cylohex-2-enyloxy)ethyl]cyclohexa-2,5-diene-l-carboxylic acid 32 and l-[2-(6,6- dimethylbicyclo[3.1. l]hept-2-en-2-ylmethoxy)ethyl]cyclohexa-2,5-diene- 1-carboxyhc acid 33 are new compounds which were prepared in four straightforward steps from cyclohexene and β-pinene respectively. The route leading to acid 32 involved the preparation of four new compounds and three new compounds were prepared during the synthesis of acid 33. When refluxed in benzene in the presence of dibenzoyl peroxide, carboxylic acid 32 generated a primary alkyl radical which cyclised to yield 7- oxabicyclo[4.3.0]-nonane in 55% yield. The tin-mediated cyclisation of 3-(2'- iodoethoxy)cyclohexene 36 yielded the same compound in 60% yield, in addition to 3- ethoxycyclohexene (12%). Similarly, carboxylic acid 33 generated a primary alkyl radical which cyclised to yield the new compound oxacyclopentane-3-spiro-2-6,6- dimethylbicyclo[3.1.1]heptane in 10% yield. The tin-mediated cyclisation of 6,6-dimethyl- 2-(2-iodoethoxymethyl)bicyclo[3.1.1]hept-2-ene 37 yielded the same spiro compound in 31% yield. EPR spectroscopic studies provided direct evidence for the formation of the cyclohexadienyl radicals from all of the carboxylic acids investigated. Carboxylic acids 15- 17 and l-[2-(ethenyloxy)benzyl]cyclohexa-2,5-diene-l-carboxylic acid 34 also generated alkyl radicals which were clearly observed by EPR spectroscopy. The carboxylic acid radical precursors would have yielded products in higher yields if the competitive loss of a hydroxyformyl radical did not occur. An account of our work directed towards the synthesis of l-phenylcyclohexa-2,5-diene-l- carboxylic acid 8 is given. Thus, 1,4-dihydrobiphenyl was deprotonated with BuLi, added to CO2 and the isomeric acid, 3-carboxylic acid-3,4-dihydrobiphenyl was removed by reacting with maleic anhydride to give the Diels-Alder adduct. 2-(Cyclohex-2-enyloxy)ethyl l-phenylcyclohexa-2,5-diene-l-carboxylate 24 was treated with dibenzoyl peroxide to afford 7-oxabicyclo[4.3.0]nonane in yields of 32-36%. A variety of N-carboalkoxy-l,2-dihydropyridines have been prepared from the reaction of pyridine and the appropriate chloroforniate in the presence of NaBH4. EPR studies have shown that these esters produce aza-cyclohexadienyl radicals on photolysis in the presence of di-t-butyl peroxide, but no decarboxylation was observed. These compounds do not generate alkyl radicals efficiently when reacted with dibenzoyl peroxide. In each case the major product identified was the corresponding benzoate ester, which resulted from the combination of an alkoxycarbonyl radical and a phenyl radical.

This thesis reports on the development and expansion of reliable synthetic di-and multi-tin precursors for the assembly of oligomeric organotin-oxo compounds in which the shape, dimension and tin nuclearity can be controlled. The reaction of polymeric diorganotin oxides, (R2SnO)m (R = Me, Et, n-Bu, n-Oct, c-Hex, i-Pr, Ph), with saturated aqueous NH4X solutions (X = F, Cl, Br, I, OAc) in refluxing 1,4-dioxane afforded in high yields dimeric tetraorganodistannoxanes, [R2(X)SnOSn(X)R2]2, and in a few cases diorganotin dihalides or diacetates, R2SnX2. This method appears to be particularly good for the synthesis of halogenated tetraorganodistannoxanes but a less suitable method for the preparation of dicarboxylato tetraorganodistannoxanes. Identification of [R2(OH)SnOSn(X)R2]2 (R = n-Bu; X = Cl, Br) and [R2(OH)SnOSn(X)R2][R2(X)SnOSn(X)R2] suggest a serial substitution mechanism starting from [R2(OH)SnOSn(OH)R2]2. A series of α, ω -bis(triphenylstannyl)alkanes, [Ph3Sn]2(CH2)n (n = 3-8, 10, 12) and some of their derivatives were synthesised and characterised. These α, ω-bis(triphenylstannyl)alkanes, [Ph3Sn]2(CH2)n were converted to the corresponding halides [R(Cl)2Sn]2(CH2)n (R = CH2SiMe3) and subsequently to the polymeric oxides {[R(0)Sn]2(CH2)n}m. Reaction of {[R(O)Sn]2(CH2)n}m with [R(Cl)2Sn]2(CH2)n. (n = 3, n' = 4 and n = 4, n' = 3) in toluene at 100°C results in a mixture of symmetric and asymmetric double ladders, where different spacer chain lengths (n and n') provide the source of asymmetry. The coexistence at high temperature of separate 119Sn NMR signals belonging to symmetric and asymmetric double ladders suggests an equilibrium that is slow on the 119Sn NMR time scale and the position of which is temperature dependent. However, 119Sn NMR spectroscopic experiments of {[R(0)Sn]2(CH2)3}m with [R(Cl)2Sn]2(CH2)n for longer spacers (n - 5, 6, 8, 10, 12) reveal that molecular self-assembly of symmetric spacer-bridged di-tin precursors of equal chain length is preferred over asymmetric species. An ether-bridged di-tin tetrachloride [R(Cl)2Sn(CH2)3]2O (R = CH2SiMe3) and its corresponding polymeric oxide {[R(O)Sn(CH2)3]2O}m were synthesised and characterised. Reaction of [R(Cl)2Sn(CH2)3]2O with {[R(O)Sn(CH2)3]2O}m results in a unique functionalised double ladder {{[RSn(Cl)](CH2)3O(CH2)3[RSn(Cl)]}O}4 whose structure in the solid state was determined by X-ray analysis. Identification of tetrameric functionalised double ladder as well as dimeric and monomeric species suggest the existence of an equilibrium in solution. The feasibility of the functionalised double ladder to form host-guest complexes with a variety of metal cations is investigated using electrospray mass spectrometry (ESMS). Evidence for such complexes is found only for sodium cations. The reaction between {[R(O)Sn]2(CH2)n}m (n = 3, 4, 8, 10) and triflic acid is described. The initial formed products [RSn(CH2)nSnR](OTf)4 are easily hydrolysed. For n = 3, self-assembly leads to a discrete double ladder type structure, {{[RSn(OH)](CH2)3[RSn(H2O)]}O}44OTf, which is the first example of a cationic double ladder. For n ≥ 3, hydrolysis gives polymeric products, as demonstrated by the crystal structure of {[(H2O)(OH)RSn]2(CH2)4-2OTf2H2O}m. Two spacer-bridged terra-tin octachlorides [R(Cl)2Sn(CH2)3Sn(Cl)2]2(CH2)n (R = CH2SiMes; n = 1, 8) and their corresponding polymeric oxides {[R(O)Sn(CH2)3Sn(O)]2(CH2)n}m were successfully synthesised and characterised. Attempts were made to synthesise quadruple ladders from these precursors. Reactions of [R(Cl)2Sn(CH2)3Sn(Cl)2]2CH2 with {[R(O)Sn(CH2)3Sn(O)]2CH2}m or (Y-Bu2SnO)3 result in, mostly insoluble, amorphous solids. Reactions of [R(Cl)2Sn(CH2)3Sn(Cl)2]2(CH2)8 with {[R(O)Sn(CH2)3Sn(O)]2(CH2)8}m or (t-Bu2SnO)s result in new tin-containing species which are presumably oligomeric. The synthesis of a series of alkyl-bridged di-tin hexacarboxylates [(RCO2)3Sn]2(CH2)n (n = 3, 4; R = Ph, c-C6H11, CH3, C1CH2) is also reported. The hydrolysis of these compounds is facile and complex. There appears to be no correlation between spacer chain length and hydrolysis product. However, the conjugate acid strength of the carboxylate does appear to be important. In general only insoluble amorphous polymeric organotin-oxo compounds were obtained.

Thesis (M.S.)--Florida State University, 2006. / Advisor: Marie E. Krafft, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed June 13, 2006). Document formatted into pages; contains xix, 119 pages. Includes bibliographical references.

In part I of this thesis, orgimotin compounds were investigated, using high resolution proton and tin 119 nuclear magnetic resonance technique. The tin 119 chemical shift of about forty organotin compounds were measured by absorption mode for the first time. The tin chemical shift and tin 119-proton coupling constant in some methyltinhalides wore found, to be solvent and concentration dependent in electron donor solvents. This dependence was attributed to the formation of higher than four coordinated complexes with solvent molecules. Equilibrium constants of the complex formation, the tin chemical shifts, and the tin-proton coupling constants of the complexes, wore obtained in a few solvents. The second-order paramagnetic chemical shifts of methyltinhaiides, methyltin cations, and five coordinated compounds were calculated and compared with the observed tin chemical shifts. Good qualitative agreements between calculated values and observed values confirmed that the second-order paramagnetic term in tin chemical shifts is dominant in the chemical shift changes in those compounds. In part II, X-ray irradiated single crystals of malonamide and cyanoacetamide were studied by electron spin resonance technique. In both cases at least two types of radicals were found. One was the usual π -electron type radical the proton coupling tensor of which had been studied, quite extensively in the past. In this study, besides the proton coupling and in the case of cyanoaecetamide, the coupling tensor for the cyano-nitrogen was also measured and discussed. The second radical found both in X-ray irradiated malonamide and cyanoacetamide was a Ϭ-electron type radical which was produced by the loss of one of the amide protons (-COṄH). The proton hyperfine coupling constant was found to be almost isotropic and very large, more than 80 gauss in both compounds. The nitrogen coupling tensor for the amide- nitrogen was found to be axially symmetric with the unique principal value equal to 36.6 gauss in the one (malonamide) and 25.4 gauss in the other (cyanoacetamide). The principal value in perpendicular direction was found to be very small but could not be determined conclusively. A semi-empirical molecular orbital calculation was performed on the fragment of Ϭ-electron radical together with perturbation through configuration interaction; the large isotropic proton coupling constants were explained theoretically. / Science, Faculty of / Chemistry, Department of / Graduate