Synthetic Studies Utilising Dehydroabietic Acid

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dc.contributor.advisor Professor R.C. Cambie en Franich, Robert Arthur en 2008-01-09T00:11:28Z en 2008-01-09T00:11:28Z en 1970 en
dc.identifier.citation Thesis (PhD--Chemistry)--University of Auckland, 1970. en
dc.identifier.uri en
dc.description.abstract This thesis is concerned with the utilisation of the natural product, abieta-8,11,13-trien-18-oic acid* (dehydroabietic acid) (1) for the synthesis of optically active steroids and diterpenoids. The work has been divided into three sections which describe transformations of rings A, B and C of abieta-8,11,13-trien-18-oic acid (1). Selective epoxidation of the alkene mixture (3-5) derived from oxidative decarboxylation of abieta-8,11,13-trien-18-oic acid (1) with lead tetraacetate has given the epoxides (64), (65), a low yield of the epoxide (66), and the pure exocyclic alkene (3). The alkene (3) was oxidised to the ketone (6) which has been previously employed as an intermediate for the synthesis of the α,β-unsaturated ketone (10). The epoxides (64) and (65) have been converted to the unsaturated ketones (89), (107), and (67), and the saturated ketones (13), (99) and (100). A study of the boron triflouride rearrangements of the three epoxides (64), (65) and (66) has been made using benzene and dimethyl suplhoxide as solvents, and pathways for the formation of the products are suggested. Peracid oxidation of the enol acetate (155) derived from the C 7-ketone (18) provided a facile introduction of oxygen substituents into the hindered C 6 position of abieta-8,11,13-trien-18-oic acid (1). By hydrogenolysis of the C 7-hydroxy substituent of the compound (162), the C 6-acetate (172) was obtained. Hydrolysis of the latter compound, and methylation of the acid formed gave the C 6-alcohol (175) which was oxidised to the C 6-ketone (176). The literature pertaining to the intramolecular functionalisation of aromatic alkyl groups has been surveyed, and, with the ultimate aim of synthesizing the aromatic steroids (237) and (249), the C 13-isopropyl group of abieta-8,11-13-trien-18-oic acid (1) has been functionalised by the application of two of the published procedure, viz. the lead tetraacetate oxidation of aromatic acids, and the thermolysis of diaxomethyl ketones. Nitration of methyl 12-acetylabieta-8,11,13-trien-18-oate (227) has given products of nitrodeacylation (44) and nitrodealkylation (266). The product of nitrodealkylation (266) has been converted to methyl 13-hydroxy-podocarpa-8,11,13-trien-18-oate (59) in 36% yield. Methylation of the phenol (59), and Birch reduction of the methyl ether (276) has given podocarp-8(14)-en-18-ol-13-one (281). Annelation of the α,β-unsaturated ketone (281) with bromoacetone was attempted in order to synthesize the steroid (284), but the only product identified was the furan (286). * The numbering system used throughout this thesis is that proposed by J.W. Rose (personal communication to Professor R. C. Cambie) in “The Common and Systematic Nomenclature of Cyclic Diterpenes” 3rd revision, Oct 1968, to be submitted to the IUPAC Commission on Organic Nomenclature. en
dc.format Scanned from print thesis en
dc.language.iso en en
dc.publisher ResearchSpace@Auckland en
dc.relation.ispartof PhD Thesis - University of Auckland en
dc.relation.isreferencedby UoA216072 en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. en
dc.rights.uri en
dc.title Synthetic Studies Utilising Dehydroabietic Acid en
dc.type Thesis en Chemical Sciences en The University of Auckland en Doctoral en PhD en
dc.subject.marsden Fields of Research::250000 Chemical Sciences en
dc.rights.holder Copyright: The author en
pubs.local.anzsrc 03 - Chemical Sciences en Faculty of Science en

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