No description available.

No description available.

No description available.

No description available.

No description available.

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1966. / Bibliography: leaves [60]-64. / x, 64 l illus

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1966. / Bibliography: leaves [114]-116. / ix, 116 l illus., tables

M.Sc. (Chemistry) / The aim of this study waa to develop new methodology for the synthesis of chiral pyrrolidine derivatives Crom monosaccharides. An overview of the stereoselectlve synthesis of pyrrolldlnes as precursors of natural compounds 11 given, as well as a summary ,of their uses in the synthesis of two groups of biologically active natural compounds and their analogues. A synthetic approach towards a pyrrolidine synthon for an ll-a.za-PG was investigated by means of stereoselective and stereospecific reactions. The ability to incorporate an N-O linkage into the synthon to allow the synthesis of a true isosteric analogue of PG F2Q , namely ll-a:a-ll-hydroxy-PG F2Q, Is a challenge that has not yet been accomplished. (IR,5R,6S)~benzoyloxymethyl-7-beI1%yloxy-3-oxo-7-aza-2-oxa-bicyclo[3.3.0]octane (162) was synthesized Cram L-arabinose. The nitrogen atom was introduced at e-l by the reaction of the furanose (140) ~itlt G-beiU.ilL1JlIJA1:4Jilllle h'ydl~hluride to Iuraish an oxime ether. Mesylatlon and subsequent reduction of the oxime double bond enabled cyclisatlon to the pyrrolidine synthon. This desired N-O linkage was thus maintained. Problems with the removal of the oxime protecting group were envisioned and, in order to overcome them, oxime ethers were synthesized Crom various hydroxylamine salts. However, some oxime ethers then cyclised to afford the I-hydroxylamino furanoses. A balance between a hogh yield of the required acyclic oxime Isomers and the easy removal of the protecting groups has yet to be achieved. Those protecting groups that allowed formation of the oxime in high yields proved difficult to remove at a later stage of the synthesis and further studies into the suitability of the various protecting groups are currently being carried out.

M.Sc. (Chemistry) / Please refer to full text to view abstract

The synthesis of exo-antl-tricyclo [3,2,1,02,4] octan-8-ol (V) and exo-anti-8-methoxy-tricyclo [3,2,1,02,4] octane (VI) was carried out by the cuprous chloride catalysed reaction of diazoraethane with anti-7-norbornenol (IV). The methyl ether (VI) was previously thought to be the endo isomer of (V). Methylene addition to the syn double bond of 7-norbornadienyl acetate (III) was accomplished using the above method to give a 5 to 1 mixture of exo-syn-tricyclo [3,2,1,02,4] oct-6-ene-8- acetate (VII) and endo-syn-tricyclo [3,2,1,02,4] oct-6-ene-8- acetate (VIII). These two acetates were inseparable but the corresponding alcohols exo-syn-tricyclo [3,2,1,02,4] oct-6-ene-8-ol (X) and endo-syn-tricyclo [3,2,1,02,4] oct-6-ene-8-ol (XI), formed by reduction of the acetate mixture with lithium aluminum hydride, could be separated by gas-liquid partition chromatography. The stereochemistry of these two products was determined by the multiplicity and by the chemical shift of the olefinic proton signals in their proton nuclear magnetic resonance spectra. Catalytic reduction of these two alcohols gave exo-syn-tricyclo [3,2,1,02,4] octan-8-ol (XIII) and endo-syn-trlcyclo [3,2,1,02,4] octan-8-ol (XIV). From the diazomethane-7-norbornadienyl acetate reaction a diadduct acetate, tetracyclo [3,3,1,02,4,06,8]nonan-9-acetate (IX), was also obtained which reduced to the alcohol tetracyclo [3,3,1,02,4,06,8] nonan-9-ol (XII). The stereochemistry of these diadducts was not determined. Acetolysis studies on the p-bromobenzene- sulfonyl (brosylate) derivative of exo-anti-tricyclo [3,2,1,02,4]octan-8-ol (V) at 200° indicate that the reaction proceeds by formation of a carbonium ion at C8, which then rearranges, destroying the cyclopropyl group. Although unchanged (V) could be obtained by lithium aluminum hydride reduction of about 80% solvolysed brosylate at 200°, none of the products of complete solvolysis could be identified. / Science, Faculty of / Chemistry, Department of / Graduate