Abstract not available.

A series-of substituted methyl 1-methylcyclohex-3-ene-1-carboxylates of the general formula have been synthesized and the proton magnetic resonance spectra measured. The ring protons were extensively coupled to each other and gave complex spectra. The 3, 5, 5'-trideutero analogues have also been synthesized. The geminal coupling constant JAB, was obtained from the AB pattern produced by the magnetically non-equivalent protons in the allylic methylene group. JAB has been found to depend on the nature of the substituent R. A Hammett correlation between JAB and sigma P, the Hammett substituent constant, had a slope or rho value of -2.9. Resonance effects were shown to be much more predominant than field effects.* Long-range coupling over four bonds has been measured between the allylic proton at C2 and the homoallylic proton at C6. The low field proton of each AB group has been tentatively assigned as being cis to the carbomethoxy group. The low field proton of the allylic methylene group showed a larger S. C. S. than the high field proton. Since the low field proton is predominantly in the pseudoequatorial position, this result is opposite to that predicted by a hyperconjugative type of interaction. The chemical shift of the olefinic proton of each compound has been found to obey the additivity scheme of Sternhell and co-workers. *Please refer to dissertation for diagram.

This thesis is concerned with the preparation of five membered ring compounds. Some 1,2,3-trisubstituted cyclopenetanes were prepared in order to get information related to conformational analysis in the reactions of centres in five membered ring compounds. 3-Acetoxycyclopentene and 3-methoxycyclopentene were used as starting materials for the preparation of these compounds. Treatment of 3-acetoxyxyclopentene and 3-methoxycyclopentene with perbenzoic acid gave the corresponding trans-oxides. The structure of these oxides were determined by chemical means. 1,2,3-Cyclopentanetriols obtained by way of wet and dry Prevost reactions of 3-acetoxycyclopentene and from the hydrolysis of trans-oxide of 3-acetoxycyclopentene were separated by partition chromatography using Celite to hold the static aqueous phase and n-butanol equilibrated with five percent boric acid solution as solvent system. Structures of 1alpha,2alpha,3beta and 1alpha,2beta,3alpha cyclopentanetriols were proved by chemical means and some solid derivatives of these compounds were prepared. The proton resonance spectra of 1alpha,3alpha-dimethoxy-2beta-acetoxycyclopentane and 1alpha-p-nitrobenzoate-2beta-bromo-3alpha-acetoxycyclopentane were taken. The reactions of above mentioned substances and other related five membered ring compounds are reported in the theses.

The reaction between cupric chloride and nitric oxide in methanol has been studied by measuring the absorption of nitric oxide per mole copper as a function of initial cupric chloride concentration. The results were interpreted by the equilibria: CuCl2+NO&rlhar2;CuCl2NO CuCl2NO&rlhar2;CuCl2- +NO+ NO++CH3OH&rlhar2;CH3 NO2+H+ Over the concentration range 0.016--0.2 M, dissociation of the nitrosyl to NO-containing species is estimated to be 35%. As the concentration is decreased further, this dissociation tends to completion. The nitrosyl of salicylal o-hydroxybenzylamine copper (II) was prepared, and the number of molecules of associated solvent determined by the mole ratio method.* The nitrosyl complexes of cupric iodide, cyanide, thiocyanate and pyridine thiocyanate have been prepared in solution. The nitrosyls of cupric iodide, cyanide and thiocyanate are extremely unstable, with a lifetime of the order of two minutes. The nitrosyl of cupric pyridine thiocyanate is stable in solution for several hours. Spectrophotometric evidence is presented for their existence. Further investigations covered cupric nitrate, hydroxide, iodate, aslicyaldoximate and dithio-oxamide. None of these compounds were observed to form nitrosyls. Consideration of the conditions under which nitrosyls may be formed has led to the suggestion that NO requires to be able to attack the fourth co-planar position. The solid nitrosyls of cupric bromide and chloride have been isolated by precipitation with petroleum ether. On drying, the solid loses associated solvent, and it is suggested that dimerization could be expected to (CuCl 2NO)2. Analysis of the solid shows that it may be isolated with one molecule of solvent attached. Solvation determination by I.R. spectra on CuCl2NO shows that one molecule of solvent is attached, with some indication of a second less strongly held. *Please refer to dissertation for diagrams.

Abstract not available.

Abstract not available.

Part I. 2-Butynoic acid, which was synthesized by the reaction of carbon dioxide with lithio methylacetylide, was converted to the methyl ester with diazomethane. This ester, when photolysed in benzene, gave 2-carbomethoxy-1-methylcyclooctatetraene. Hydrogenation of 2-carbomethoxy-1-methylcyclooctatetraene confirmed the presence of four double bonds and gave a single product, cis-2-carbomethoxy-1-methylcyclooctane. 2-Carbomethoxy-1-methylcyclooctatetraene was converted to the alcohol by metal hydride in ether. It was found that aluminum hydride gave better yields than lithium aluminum hydride. The reaction of phosphorus tribromide with this alcohol gave the bromo compound which, when treated with trimethylamine in methanolhexane, gave 1-methyl-2-N,N,N-trimethylaminomethylcyclooctatetraene bromide, This quaternary bromide on treatment with an aqueous slurry of silver oxide gave the quaternary hydroxide, which was readily converted to 1,2-dimethylenecyclooctatriene by pyrolysis at reduced pressure. The mass spectra of 2-carbomethoxy-1-methylcyclooctatetraene, 2-hydroxymethyl-1-methylcyclooctatetraene, and 1,2-dimethylenecyclooctatriene were obtained and breakdown patterns were proposed. 1,2-Dimethylenecyclooctatriene was shown to be monocyclic by the n.m.r. spectrum, although the possibility that the monocyclic form is in equilibrium with a small amount of a bicyclic form is not excluded. An attempt to obtain a bicyclic form by photolysis was unsuccessful. 1,2-Dimethylenecyclooctatriene was shown to be fairly stable thermally but extremely sensitive to oxygen. The infrared spectrum indicated that the molecule is not highly strained. Molecular orbital calculations were performed on planar 1,2-dimethylenecyclooctatriene. The total pi energy, the delocalization energy, the bond orders and the free valences were calculated. Despite a high calculated delocalization energy for the planar form, the molecule apparently prefers a less strained non-planar shape as is shown by the ultraviolet spectrum. The reactions of a variety of pi systems with dienophiles were compared with the reaction of 1,2-dimethylenecyclooctatriene with tetracyanoethylene. Part II. The addition of ketene to cis, trans-1,3-cyclooctadiene gave trans-bicyclo[6.2.0]dec-2-en-9-one. Arguments were presented supporting the assignment of the position of the double bond as gammadelta to the carbonyl group and the fusion of the rings as trans. The reduced product, bicyclo[6.2.0]dec-9-one was prepared. The reduction confirmed that the original product had only one double bond. cis-Bicyclo[6.2.0]dec-2-en-9-one was obtained by passing a dilute solution of trans-bicyclo[6.2.0]dec-2-en-9-one in pentane through an alumina column. Wolff-Kishner reduction gave bicyclo[6.2.0]dec-2-ene which was used for dehydrogenation studies. Dehydrogenation by rhodium on alumina gave a small amount of azulene but none of the desired bicyclo[6.2.0]decapentaene.

Abstract not available.

A quantitative conformational analysis was made of the anomerization equilibria of the acetylated aldopyranoses. The following non-bonded interaction energies were obtained, based on the assumption that the difference in free energy between the anomeric pairs can be taken as equal to the difference in non bonded interactions. (1) The anomeric effect, 1290 Gals./mole. (2) An acetoxymethyl group on carbon 5 enhances the anomeric effect by 220 call,/mole. (3) The skew interaction between two acetoxy groups, O/O-H/H, is 540 cals,/mole. (4) The diaxial interaction between an acetoxy group and a hydrogen atom, H:O-H:H, is 180 cals./mole. (5) The diaxial interaction between two acetoxy groups, O:O-H:H, is 2020 cals/mole. These interaction energies are all related to the interaction term H/O-H/H, that is the skew interaction between an acetoxy group and a hydrogen atom relative to the same inter action between two hydrogen atoms. The above values for the interaction energies are based on the assumption that the value of H/O-H/H is negligibly small. This type of assumption has been made by all previous workers in the field of conformational analysis and is required for a comparison of the values presently obtained with those values of similar interactions reported in the literature. The acetylated amono-sugars with an acetamido group on carbon. 2 or 3 were found to undergo anomalous anomerization reactions, These results could be due to the formation of stable oxazolinium or oxazinium ions in the anomerization media. The relative stabilities of the transition states in the anomerization of the acetylated aldopyranoses were examined in a number of different ways. It was concluded that the results would best be rationalized on the basis of a bimolecular mechanism. Conformational analyses of the transition states indicated that the activated complexes of the aldopentopyranose tetraacetates may assume a half-chair form. However, a deformed chair seemed more plausible for the transition states of the al dohexopyranose pentaacetates. The reason for this difference between the pentoses and hexoses is discussed. The reaction of the base-catalyzed anomerization of the D-glucopyranose pentaacetates was investigated. T he amino-sugar moieties from the hydrolysis of the new antibiotic kanamycin were identified as 3-D-glucosamine and 6-D-glucosamine. The configuration of 1,2;5,6-diisopropylidene-3-deoxy-3-amino-alpha-D-allofuranose was established. This proves that inversion occurs in the replacement of a tosyloxy group on secondary carbon atoms with ammonia or hydrazine and provided unequivocal identification of 3-D-glucosamine.

A steady-state kinetic study has been made of the trypsin-catalyzed hydrolysis of N-benzoyl-L-alanine methyl ester, at pH values ranging from 6-10. From the rates were calculated, at each pH values of k˜c/K˜m, k˜c and K˜m (=k˜c(k˜-1+k˜2)/k˜ 1k˜2). The pH profiles of these parameters provide pK values for the groups that ionize in the free enzyme and in the acylenzyme. The kinetic results on the acid side imply that there is a group of pK ≃ 7 in trypsin, presumably the imidazole function of a histidine residue, and that this group is involved in acylation and deacylation, both of which can only occur if it is unprotonated. The behaviour on the basic side revealed a decrease in kc at high pH corresponding to a value of pK ≃ 9.5, whereas k˜ c/K˜m showed sigmoid pH dependence. This pK was related to the alpha-amino group of the N-terminal isoleucine residue. The specific levorotation of trypsin and trypsinogen has been measured as a function of pH over the pH range 5-11. The change in specific rotation of trypsin follows the ionization of a single group with a pK(app) of 9.4 which was not revealed by the corresponding curve for trypsinogen. At pH 11, the specific rotation of trypsin, its zymogen and its phosphorylated derivative were approximately the same, suggesting similar conformations for all three forms of the protein. The pH-dependence curves of the specific rotation of trypsin in the presence of reversible competitive inhibitors were found to be displaced to a more alkaline pH. This was interpreted to indicate a conformational stabilization as the result of enzyme-inhibitor complex formation with a consequent increase in the pK(app) of the group revealed by the free enzyme. An interpretation of the kinetic and optical rotary results that is consistent with all available information is that the group of pK ≃ 9.5 (presumably the -NH3+ function of the terminal isoleucine residue) controls the conformation and thereby the activity of the enzyme in alkaline solution. The transient-phase kinetics of the trypsin-catalyzed hydrolysis of N-carbobenzoxy-L-alanine-p-nitro-phenyl ester have been studied using a stopped-flow technique. Under conditions of excess enzyme concentration, the pH-dependencies of k˜2 and K˜ m (=k˜-1+k˜2)/k˜1) have been obtained without the need to make any assumptions as to the relative magnitude of k˜3. From the results it was concluded that a group of pK = 6.9 participates in acylation and that the same group is not involved in Michaelis-complex formation. On the basis of the steady-state work, this group has already been postulated to be the imidazole function of the histidine residue. A least-squares-fit computer program was developed to analyze the kinetic rate measurements directly and was used in place of the traditionally employed Guggenheim method. The effect of organic solvent on the pre-steady state parameters has been investigated for solvent concentrations varying from 1-20% (v/v) isopropyl alcohol. The changes in k˜2, K˜m and k˜ 2/K˜m could be formally correlated with the reciprocal of the dielectric constant of the solvent mixture, indicating an increase in electrostatic interactions. It was concluded that the observed decrease in both binding and the rate of hydrolysis of N-carbobenzoxy-L-alanine-p-nitrophenyl ester can be justified by a loss in conformational integrity of the enzyme. This is the result of increased free-energy contributions due to electrostatic and hydrophobic interactions with little or no effect due to hydrogen bonding. The chemical and mechanistic evidence for reactions catalyzed by trypsin and chymotrypsin has been reviewed in some detail and is considered with reference to the structure of chymotrypsin as determined by X-ray studies. Conclusions have been drawn about the detailed nature of the processes of Michaelis-complex formation, acylation and deacylation which are incorporated in a concerted reaction mechanism. Although there are significant differences between the two enzymes as far as specificity and pH effects are concerned, it has been concluded that their mechanism of catalysis is the same.