Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 152-155). Also available via the Internet.

The first conduritol aziridine (1,2-dideoxy-1,2-epimino-myo-inositol, 1) was synthesized in seven steps from myo-inositol (2) and inhibits pABG5 β-glucosidase and yeast ⍺-glucosidase irreversibly. 1,2-0-Cyclohexylidene-myo-inositol (3) was obtained by reaction of 2 with cyclohexanone. Benzylation of 3 followed by hydrolysis of the ketal gave l,4,5,6-tetra-0-benzyl-myo-inositol (5). The two free hydroxyl groups in 5 were methanesulfonylated and the axial mesyl group in l,4,5,6-tetra-0-benzyl-2,3-di-0-methanesulfonyl-myo-inositol (12) was selectively displaced by an azido group. The resulting 1-azido-2,3,4,5-tetxa-0-benzyl-1-deoxy-6-0-methanesulfonyl-scyllo-inositol (13) was hydrogenated in the presence of HC1 to give 1-amino-1-deoxy-2-0-methanesulfonyl-scyllo-inositol (24) hydrochloride. Cyclisation of 24 under basic aqueous conditions yielded DL-1. [Formula Omitted] The dissociation constant Ki and the inactivation rate constant ki for inactivation of pABG5 β-glucosidase by 1 were calculated to be 3.0 mM and 0.077 min⁻¹ respectively. For yeast ⍺-glucosidase inactivation, values of Ki, and ki were found to be 9.5 mM and 0.39 min-1 respectively. Finally, 24 and 31 were tested as reversible (non-covalent) inhibitors of both the glucosidases and the respective inhibition constants (Ki) determined. / Science, Faculty of / Chemistry, Department of / Graduate

Thesis (Ph.D.)--Tufts University, 1999. / Adviser: Marc d'Alarcao. Submitted to the Dept. of Chemistry. Includes bibliographical references (leaves 123-128). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

The inososes are a group of compounds, containing six-membered rings that have five hydroxyls (four for the deoxyinososes) and a carbonyl. Due to the relative ease of their reduction to inositols, a study aimed at the potential preparation of these useful natural products was undertaken. The constitution of the hydroxyls shows that either the α or β face can react with an appropriate reducing agent, such as Raney Ni/H₂, to yield the expected inositol. It has been shown by others that, by using Raney Ni/H₂ as the reducing agent equilibrium between the two chair conformations can be established and the carbony! can be reduced stereoselectively. This is shown in the example below for allo-1-inosose: [See figure] Molecular modeling with PCMODEL© which invokes MMX calculations was performed to permit a distinct prediction of the course and the stereochemical outcome of the reduction of the inososes. Several inososes and deoxyinososes were modeled to demonstrate the ability of MMX calculations to predict the stereochemical outcome of the reduction. Based on the results of molecular modeling, which include the heats of formation, and the strain energies, the lowest energy form was determined for each inosose and deoxyinosose. With the lowest energy form predicted, stereochemistry of the inositol or deoxyinositol product was predicted. In one case, a comparison with known experimental results was made. / Master of Science

Cyclitols have attracted a great deal of attention in recent years because of diverse biological activities exhibited by them and also synthetic usefulness in the synthesis of other natural compounds or pharmaceuticals. The presence of hydroxymethyl groups in many cyclitols units building natural products is also attracting a remarkable attention. In this study, novel synthetic strategies leading to cyclitol derivatives including hydroxymethyl groups were investigated and the syntheses of bis-homoinositol derivative 127 and hydroxymethyl containing conduritol derivative 137 were achieved successfully. For the synthesis of bishomo-chiro-inositol (127), lactone derivative 132 was synthesized as key compound. The molecule was functionalized with the use of photooxygenation and epoxidation reactions to get target stereochemistry. For the synthesis of hydroxymethyl containing conduritol 137, hydroxymethyl substituted p-benzoquinone derivative 136 was synthesized as a key compound. Bromination of related double bond, reduction of carbonyl groups and the following substitution of bromine atoms form the basis of our strategy. As a result we enabled to synthesize novel cyclitol derivatives stereoselectively by using commercially available starting compounds and well known reactions.

Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 104-124). Also available on the World Wide Web.

Cette thèse est divisée en quatre parties. Une nouvelle méthodologie de substitution nucléophile directe d’alcools allyliques primaires (MBH) catalysée par le système bicatalytique Fe(III)/BF3 suivie d’une application à la synthèse des structures de type pyrrolidines à partir d’adduits de MBH a tout d’abord été développée. La seconde concerne l’étude de la stabilité ou de l’instabilité des réactifs allénylcuivres. Cette étude a permis de déduire une instabilité configurationnelle totale des allénylcuivres à une température réactionnelle aussi basse que -90°C ainsi que le rôle crucial du contre ion Li+ dans ce processus. Dans la troisième partie, un processus de dédoublement cinétique dynamique d’allényles cuivres préparés in-situ sur les aldéhydes et imines a permis la construction des dérivés aminoalcools homopropargyliques de façon très directe, efficace, diastéréoséléctive, énantiosélective et diversifiée. Dans la dernière partie, ces précurseurs aminoalcools homopropargyliques énantioenrichis synthétisés ont conduit aux dérivés cyclohexènes C-7 cyclitols par une métathèse cyclisante ényne catalysée par le catalyseur au ruthénium. Enfin, des perspectives de travail et une conclusion générale sont proposées. / This thesis is divided into four parts. A new methodology of direct nucleophilic substitution of primary alcohols of MBH adduct catalyzed by Fe (III) / BF3 bicatalytic system followed by an application to the synthesis of pyrrolidine derivatives from MBH adducts was first developed. The second part deals with the study of the configurational stability or instability of allenylcuprate reagents. This study allowed to elucidate a total configurational instability of the allenylcuprate species to temperatures as low as -90 °C. The crucial role of the Li+ counter-ion in this process was also demonstrated. In the third part, a dynamic kinetic resolution of allenyl copper species prepared in-situ upon addition to chiral aldehydes and imines allows the construction of homopropargylic aminoalcohol derivatives in a very direct, effective, diastereoselective, enantioselective and diversified process. In the last part, these homopropargylic enantioenriched aminoalcohols were converted to cyclohexene derivatives C-7 cyclitols by a ruthenium-catalyzed ring closing enyne metathesis (RCEYM).

ABSTRACT ADDITION OF CARBONYL COMPOUNDS TO THE CYCLIC OLEFINS: SYNTHESIS OF CYCLITOLS Altun, Yasemin M.S., Department of Chemistry Supervisor: Prof. Dr. Metin Balci October 2008, 160 pages Cyclitols have attracted a great deal of attention in recent years owing to biological activities exhibited by them and also their usefulness in the synthesis of other natural products and pharmaceuticals. Carbasugars are also a derivative of cyclitols and they are cyclic monosaccharide analogues which posses &amp / #8211 / CH2OH group in their structure. In this study, novel synthetic strategies leading to cyclitol derivatives were investigated and the synthesis of tetraol (72) and pentaol (73) derivatives containing &amp / #8211 / CH2OH group were achieved successfully. Moreover, by the use of manganese(III) acetate oxidation reactions having considerable synthetic utilities in organic chemistry we developed new synthetic methodologies for the cyclitol derivatives. 1,3- and 1,4-Cyclohexadiene (71 and 10) were synthesized from easily available starting materials in order to be used as key compounds. The use of manganese(III) acetate oxidation reaction provides the creation of &amp / #8211 / CH2OH group and one of the hydroxyl groups and the remaining hydroxyl groups were introduced into the key compounds by the use of singlet oxygen reaction. As a result of this, we had considerable advance in the synthesis of cyclitol derivatives.

No description available.

This thesis sought to expand upon the synthetic application of the underexploited ipso, ortho diene cis-diol microbial arene oxidation product from benzoic acid. The microbial oxidation of benzoic acid by mutant strains of bacteria to give the ipso, otho diene cis-diol may be considered to be a green and clean method. This biocatalytic route yields large quantities of an enantiopure chiral building block, which is not assessable via traditional synthetic methods. The fermentation product has seen application towards the synthesis of aminocylitols, which have been tested for their biological activity. Attempts to synthesise the fully oxygenated counterparts, cyclitols, were investigated. Expansion of previous work using a bromine substituted derivative led to a range of cross-coupled and iron co-ordinated products. Finally, a range of novel chiral acids and ketones were synthesised and evaluated for their catalytic activity towards asymmetric epoxidation.