Structure and Synthesis of Some Liverwort Metabolites

Salamani, Ahmid (1988) Structure and Synthesis of Some Liverwort Metabolites. MSc(R) thesis, University of Glasgow.

Abstract

This thesis consists of four chapters. The first chapter, which is a General Introduction, deals with (i) the nature of secondary metabolites and (ii) the terpenoids and aromatic constituents of the liverworts. Chapter 2 describes several efforts to synthesise a lunularic acid derivative which occurs in the liverwort Plagiochila spinulosa. A Wittig reaction of 2-nitroveratraldehyde and 4-methoxybenzyl phosphonium chloride afforded a mixture of stilbenes which on reduction gave 2-amino-3,4,4'-trimethoxybibenzyl. This amino-bibenzyl was subjected to a Sandmeyer reaction in the hope of producing 2-cyano-3,4,4'-trimethoxybibenzyl. Unfortunately, the desired compound was obtained only in very low yield. The major product was 3,5,6-trimethoxy- 9,10-dihydrophenanthrene, the result of a Pschorr cyclisation. A similar Wittig route was used to prepare 2- bromo-3,4,4'-trimethoxybibenzyl. Attempts at carboxylation resulted only In debromination. Chapter 3 concerns a discussion of the constituents of Plagiochila spinulosa. Five dihydrophenanthrene derivatives were isolated together with methyl 2-methyl-3,4-methylene-dioxy-6-methoxybenzoate and an unusual natural product spinuloplagin B which is a diterpenoid-bibenzyl conjugate. A synthesis of 2-hydroxy-3,7-dimethoxy-9,10,-dihydrophen-anthrene is also described. The final chapter considers the metabolites of Frullania tamarisci. In addition to the known compounds (-) frullanolide and tamariscol, a new dimeric sesquiterpenoid lactone was isolated.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Keywords: Biochemistry
• Date of Award: 1988
• Depositing User: Enlighten Team
• Unique ID: glathesis:1988-77814
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jan 2020 11:53
• Last Modified: 14 Jan 2020 11:53
• URI: https://theses.gla.ac.uk/id/eprint/77814