Studies in the Terpenoid Field

Donoso, Cecilia Labbe (1979) Studies in the Terpenoid Field. PhD thesis, University of Glasgow.

Abstract

This thesis consists of a General Introduction, dealing briefly with the biogenesis of terpenoids, and nine chapters. Chapters I to VII are concerned with the chemistry of tetranortriterpenoids, a group of modified triterpenoids from the Neliaceae and Rutaceae families. The present state of knowledge of these compounds is reviewed in Chapter I. This is followed by discussions of the results of investigation into the tetranortriterpenoid constituents of the wood and seeds of Chisocheton paniculatus and the seeds of Chukrasia tabularis (Chapters II and III). Fifteen new compounds v/ere isolated from these sources and their structures elucidated mainly by use of 1H and 13C n.m.r. spectroscopy. Chapter IV describes the several new additions to the small group of tetranortriterpenoids, related to prieurianin, which exist in solution at room temperature as a mixture of sterically hindered conformers. A detailed discussion of the alkaline hydrolysis products of several members of this group is included. Revised structures for atalantin and atalantolide, from Atalantia nonophylla, are proposed in Chapter V. Chapter VI is concerned with the interrelation of swietenine and swietenolide, the major tetranortriterpenoids of the seeds of Swietenia macronhylla, and Chapter VII with the structure of ekebergins I and II, complex tetranortriterpenoids from seeds and wood of Ekeberia Senegal-ensis. Detailed consideration of the spectroscopic properties of these compounds leads to biogenetically acceptable structures. Two casbene-derived diterpenoids, jatropholones A and B, from the roots of Jatropha gssypiifolia, form the subject matter of Chapter VIII. The structures of these compounds have the novel feature of a fully substituted cresol ring and were confirmed by X-ray analysis of jatropholone B acetate. The final chapter deals with a coumarin from Leonotis nepetaefolia. The structure was assigned by 1H n.m.r. and confirmed by synthesis of 2'-hydroxy- 4',5'-dimethoxy-6'-methylacetophenone, the compound obtained on hydrolysis of the natural product.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry
• Date of Award: 1979
• Depositing User: Enlighten Team
• Unique ID: glathesis:1979-78804
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 14:52
• Last Modified: 30 Jan 2020 14:52
• URI: https://theses.gla.ac.uk/id/eprint/78804