This investigation focussed on the inclusion and resolution ability of (2R,3R)-1,1,4,4-tetraphenylbutane-1,2,3,4-tetraol (TETROL), studies on the stoichiometry of its derivatives and the formation of inclusion compounds for single crystal analysis. The guest compounds that featured in the main study were cyclohexanone, 2-methylcyclohexanone, 3-methylcyclohexanone and 4-methylcyclohexanone. It was found that 3- and 4-methylcyclohexanone were trapped in their energetically unfavourable axial conformations in the inclusion crystal. Resolution experiments proved that (2R,3R)-1,1,4,4-tetraphenylbutane-1,2,3,4-tetraol can be used as a resolving agent for 2- and 3-methylcyclohexanone, with ee values of 13% and 22%, respectively (according to the method of Hiemstra), in favour of the R-enantiomer. Single crystal X-ray diffraction (SCXRD) studies, however, showed that 2-methylcyclohexanone was resolved with an ee of 30% in R. An ee of 56% in R was obtained for 3-methylcyclohexanone. Enantiomer enrichment of 2-methylcyclohexanone was achieved in basic medium (ee of 18% according to the method of Hiemstra) and showed that by using the host in either half or double the molar ratio of the guest, a higher ee was obtained than for a 1:1 ratio. The following TETROL derivatives were also synthesized and their stoichiometries with various guest compounds were determined: (2R,3R)-1,1,4,4-tetra(naphthalen-1-yl)butane-1,2,3,4-tetraol; (2R,3R)-1,1,4,4-tetra(naphthalen-2-yl)butane-1,2,3,4-tetraol; (2R,3R)-1,1,4,4-tetra(p-anisyl)butane-1,2,3,4-tetraol; (2R,3R)-1,1,4,4-tetra(p-tolyl)butane-1,2,3,4-tetraol; (2R,3R)-1,1,4,4-tetra(m-tolyl)butane-1,2,3,4-tetraol and; (2R,3R)-1,1,4,4-tetra(o-tolyl)butane-1,2,3,4-tetraol.

No description available.

Chapter 1 contains a very brief overview of 3,3-disubstituted azetidinones. Also included in this chapter are the approaches to 'hybrid' azetidinones, i.e. those which contain the structural features of more than one class of azetidinones. Finally the target molecules for the present studies are listed. Chapter 2 contains details of use of various 2,3-dihydroxybutyric acid derivatives in enantioselective syntheses of 3-alkoxyazetidinones with an additional substituent at position 3. In chapter 3 similar studies on threonine derivatives for the syntheses of 3-amino-3-hydroxyethylazetidinones are described. These studies were only partially successful. In chapter 4 a systematic approach towards the syntheses of 3-alkoxyazetidinones is described. The steps involved were the formation of the C-3 carbanion from the parent azetidinones, reaction with acetaldehyde, oxidation of the resulting 3-alkoxy-3-hydroxyethylazetidinones and finally the reduction of the acetyl compound in a non-chelation controlled manner. It has been possible to synthesize protected 3-amino-3-hydroxyethylazetidinones by a similar series of reaction and the results are presented in chapter 5. Chapter 6 has details of syntheses of 3-hydroxy, 3-hydroxy-3-hydroxyethyl, 3-hydroxy-3-allyl and 3-$\sp\prime$epoxy$\sp\prime$azetidinones. Chapter 7 contains results of a detailed study on the impact of various variables on the non-chelation controlled reduction of 3-acylazetidinones (which have an additional substituent at 3-position). Chapter 8 is about the use of N, N-dimethylchloromethylenimnium chloride for the purpose of activating carboxylic acids for their final conversion to azetidinones. An attempt was made to determine the nature of the white solid obtained on reaction of DMF with oxalyl chloride, and the product of reaction between this white solid and a carboxylic acid.

Analogues and derivatives of naturally occurring $\alpha$-terthienyl 3 have been synthesized by using the nickel-catalyzed Grignard-Wurtz cross-coupling reaction. This method has proven useful for the introduction of non-polar substituents on 2-bromothiophene which upon subsequent cross-coupling with 5-iodo-$\alpha$-dithienyl 185 led to a successful variety of 5-substituted $\alpha$-terthienyls. Derivatives of $\alpha$-terthienyl bearing polar functional groups were synthesized either by: (1) introduction of electron-withdrawing and electron-donating at C-5 and C-5$\sp{\prime\prime}$; or (2) chain extension from an appropriate substituted derivatives. In order to establish structure/activity relationships, various substituent at C-5 on the aromatic ring were made. Among the derivatives of $\alpha$-terthienyl, compound 165 was synthesized by the palladium-catalyzed coupling reaction with CuI. By adapting this methodology on $\alpha$-dithienyls, the reaction was found to be useful for coupling aryl halides such as 5-iodo-$\alpha$-dithienyl 185 with a variety of substituted 1$\sp\prime$-alkynes derivatives. A series of functional $\alpha$-dithienyl acetylene derivatives were made. The biological activity of $\alpha$-terthienyl and $\alpha$-dithienyl derivatives, as determined by feeding trials with the mosquito larvae (Aedes atropalpus) and brine shrimp, is discussed in light of the relative toxicities of these compounds.

In this work it will be shown that Fe(CO)$\sb2$(NO)$\sb2$ mediated allylic alkylation reactions proceed via an intermediate which is neither an $\eta\sp3$-allyliron complex nor an $\eta\sp2$-allyliron complex. Rather, (Fe(CO)(NO)$\sb2$DMM)$\sp-$Na$\sp+$ has been identified as the catalytic intermediate. This provides the first evidence of an interaction between the nucleophile and the metallic center in reactions involving iron nitrosyl complexes. The study of the Fe(CO)$\sb3$(NO)$\sp-$Na$\sp+$, geranyl acetate, and NaDMM system was studied in order to elucidate the catalytically active species. Although it was determined that Fe(CO)$\sb3$(NO)$\sp-$Na$\sp+$ served as the precursor of a catalytic species X, the nature of X remains unknown.

The new disaccharides, crystalline 6-deoxy-$\alpha$-D-gluco-heptopyranosyl 6-deoxy-$\alpha$-D-gluco-heptopyranoside (36) and the corresponding dicarboxylic acid (6-deoxy-$\alpha$-D-gluco-heptopyranosyluronic acid) 6-deoxy-$\alpha$-D-gluco-heptopyranosiduronic acid (5) were synthesized. Preparation of per-O- acetyl-$\alpha$,$\alpha$-trehalose 6,6$\sp\prime$-ditriflate 15 from known 2,3,4,2$\sp\prime$,3$\sp\prime$,4$\sp\prime$- hexa-O-acetyl-$\alpha$,$\alpha$-trehalose, followed by cyanide displacement in the former and subsequent hydrolysis produced 5. The latter was acetylated to give the 2,3,4,2$\sp\prime$,3$\sp\prime$,4$\sp\prime$-hexaacetate 12 of 5 which was reduced to furnish the disaccharide 36. This approach was also extended to synthesize the analogous 2,3,4,2$\sp\prime$,3$\sp\prime$,4$\sp\prime$-hexabenzyl ether of the dinitrile 28 which was similarly hydrolysed, but only to the stage of the corresponding diamide. The peracetylated dicarboxylic acid 12 was converted to the dichloride and subsequently esterified with 1-octanol, to form the di-octyl ester. Similar esterification with C$\sb $, C$\sb $, C$\sb $ and C$\sb $ 1-alkanols produced the analogous diesters. Three new mycolyl derivatives were obtained in high yields. (Abstract shortened by UMI.)

$\alpha,\beta$-Unsaturated thioamide, thioester and thione iron tricarbonyl complexes 1-13 were prepared from the free ligands and iron pentacarbonyl using photolysis or diiron nonacarbonyl using thermolysis. X-ray crystal structures were obtained for the free ligand 2$\sp\prime,$ (PhCH=C(Ph)C(S)NEt$\sb2$), and for complexes 1 and 2, $\rm\lbrack \overline{\overline{Fe(PhCH}{=}CHC(S})NEt\sb2)$(CO)$\sb3\rbrack$ and $\rm\lbrack \overline{\overline{Fe(PhCH}{=}C(Ph)C(S})NEt\sb2)$(CO)$\sb3\rbrack$ respectively. Thioamide and thioester iron tricarbonyl complexes gave triphenylphosphine substituted complexes 17-19 resulting from loss of a carbon monoxide ligand by photolysis or thermolysis. It was not possible to substitute more than one triphenylphosphine into the complexes. Thioamide and thioester ligands could be removed from the iron tricarbonyl fragment using ceric ammonium nitrate, hydrogen peroxide, m-chloroperbenzoic acid, or thermolysis. The best results were obtained with ceric ammonium nitrate, which minimized conversion of the C=S functional group to C=O. Thioester complex 10, $\rm\lbrack \overline{\overline{Fe(PhCH}{=}CHC(S})OEt)(CO)\sb3\rbrack,$ reacted with hydrogen peroxide or m-chloroperbenzoic acid to give the sulphine complex 20, $\rm\lbrack \overline{\overline{Fe(PhCH}{=}CHC(S}{=}O)OEt)(CO)\sb3\rbrack.$ Nucleophiles reacted with thioamide and thioester iron tricarbonyl complexes at room temperature affording 1,4-Michael addition products free of metal coordination. At $-$78$\sp\circ$C, nucleophiles reacted with thioamide iron tricarbonyl complexes forming 4-oxo-thioamide non-metal coordinated products. An electrophile reacted with thioester tricarbonyl complex 10 to give an S-alkylated cationic complex 21, $\rm\lbrack\lbrack\overline{\overline{Fe(PhCH}{=}CHC(S} {\sp+}$-Me)OEt)(CO)$\sb3 \rm\rbrack \lbrack BF\sb4\sp-\rbrack\rbrack.$ Alkynes added to the metal-coordinated olefin of $\alpha,\beta$-unsaturated thioamide iron tricarbonyl complexes 1, 4, $\rm\lbrack\overline{\overline{Fe(MeCH}{=}CHC(S})NEt\sb2)$(CO)$\sb3\rbrack,$ and 7, $\rm\lbrack\overline{\overline{Fe(MeCH}{=}CHC(S})N(Ph)$(Me))(CO)$\sb3\rbrack,$ generating complexes 22-26 possessing a cyclopentenone ligand. An X-ray crystal structure was obtained for complex 22. Silicon alkoxides were used as a source of alkoxide to prepare carboxylic esters in good yields from benzylic bromides and carbon monoxide catalyzed by a rhodium (I) complex under mild conditions.

A systematic investigation has been carried out on the palladium-catalyzed thiocarbonylation and related reactions of unsaturated substrates such as propargylic and allylic alcohols, 1,2- and 1,3-dienes, and conjugated enynes with thiols and carbon monoxide. It has been first demonstrated that the reaction of allylic alcohols with thiols and CO in the presence of catalytic quantities of Pd(OAc) 2 (3 mol%), triphenylphosphine (12 mol%), and p-TsOH (5 mol%) leads to a novel reaction, namely thiocarbonylation, to afford beta,gamma-usaturated thiol esters in good to excellent yields. Other catalyst systems such as Pd 2(dba)3·CHCl3/PPh3/p-TsOH, Pd(PPh 3)4/p-TsOH, and Pd(OAC)2/dppb/ p-TsOH are also effective for this transformation. The thiocarbonylation reaction is believed to proceed via a eta3-allylpalladium intermediate. The reaction occurs in a highly regioselective manner, at the least hindered allylic terminal carbon of the substrate, to give the products. The new carbonylation procedure was readily applied to a variety of allylic alcohols, and to both aromatic and aliphatic thiols. Palladium (0) as well as palladium (II) complexes with added phosphine ligands catalyze the thiocarbonylation of propargylic compounds. Depending on the reaction conditions employed, the reaction can afford mono- and di-thioesters or beta-thio-substituted gamma-lactones as the principal products in good yields, respectively. Thus, in the presence of 3 mol% of Pd(OAC)2, 5 mol% of p-TsOH, and 12 mol% of PPh3, propargylic alcohols react with thiols in THF under 400 psi of carbon monoxide at 100°C to give monothioesters in excellent yields. beta-Thio-alpha,beta-unsaturated-gamma-lactones can be prepared in high yields by the thiolactonization of propargylic alcohols using Pd(PPh3)4 as the catalyst and DME as the solvent. Propargylic mesylates undergo dithiocarbonylation when they are treated with catalytic amounts of Pd(PPh3)4. This reaction exclusively gives dithioesters under milder conditions (90°C, 400 psi). A series of mono- and di-substituted allenes undergo direct thiocarbonylation with thiols and carbon monoxide to form the corresponding unsaturated thioesters in 73--94% isolated yields. This reaction requires catalytic quantities of Pd(OAC)2 (3 mol%) and triphenylphosphine (12 mol%) in THF under an atmosphere of CO (400 psi) at 100°C for 48 h. The reaction is believed to proceed via pi-allylpalladium complex. The reaction exhibits high regioselectivity, in which the thiophenyl group adds to the less substituted double bond of allenes. (Abstract shortened by UMI.)

The Diels-Alder reaction has proven to be an invaluable tool in the arsenal of the synthetic organic chemist for the relatively facile construction of cyclic cores. However, the utility of this reaction is not without its shortcomings. Lack of regio and stereoselectivity are two problems that are often encountered with asymmetric dienophiles. Although Lewis acids have been successfully employed to control the selectivity of Diels-Alder reactions involving activated dienophiles, there is little precedent in the literature for their use with dienes containing a tertiary alcohol functionality, due to elimination complications. To this end, a new method has been developed, and reported herein, for the control of both the regio and facial selectivity of the Diels-Alder reaction via a Lewis acid tether to the dienophile directed by the tertiary alcohol on the diene.* *Please refer to dissertation for diagrams.

In the first part of this thesis, a series of rigid glycodimers were synthesized from sugar alkenes and alkynes, using transition metal catalyzed reactions. The synthesis of these dimers depended on the formation of a new carbon-carbon bond between their monomeric units. Sugars containing terminal alkenes were homodimerized using the olefin metathesis reaction, catalyzed by Grubbs' ruthenium catalyst. Terminal alkene carbohydrate derivatives were also coupled with aryl halide carbohydrates by the Heck coupling reaction, using Pd (0) catalyst, to form homo- and hetero-carbohydrate dimers selectively. Glycodimers were also obtained from sugar alkynes, using the Sonogashira coupling reaction. The dimerization of aryl halide carbohydrate derivatives using Pd (0) catalyst, and the cyclotrimerization of alkyne carbohydrates, using Grubbs' catalyst, were also attempted but were not successful. In the second part of this thesis, phenylethanoid glycosides were synthesized by glycosidation reactions. This family of compounds was shown to have numerous biological activities. A multi-step synthesis of Echinacoside, a phenylethanoid glycoside, was attempted.