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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Variations in alkaloidal constituents of plant tissue cultures

Essa, A. K. January 1987 (has links)
No description available.
12

Synthetic approaches to the alkaloid himbacine

Bennett, P. A. R. January 1988 (has links)
No description available.
13

Tropane alkaloid production in immobilized plant cell cultures

Collinge, Margaret Ann January 1987 (has links)
No description available.
14

Synthetic studies toward palau ne and enantioselective total synthesis of biogenetically related (+)-phakellin and (+)-monobromophakellin

Wang, Shaohui 15 May 2009 (has links)
Oroidin alkaloids, also known as pyrrole-imidazole alkaloids, have become a hot area of chemical and biological research due to their diverse and intriguing structural features and biological activities. Palau'amine (i), one of the hexacyclic oroidin-derived secondary metabolites, contains a fully substituted chloro-cyclopentane ring, a piperazinone moiety and two cyclic guanidines. With the uniqueness and complexity of its structure, palau’amine has been a synthetic challenge and has not yet succumbed to total synthesis. The overall objective of this work was to explore synthetic pathways toward palau’amine and biogenetically related congeners. Most of the work was focused on developing a synthetic pathway for the palau’amine structure proposed in its isolation report dated back to 1993. Starting from a Diels-Alder adduct (iii), oxidation/chlorination followed by phakellin (ii) annulation afforded an advanced pentacyclic intermediate possessing all the carbon framework and all but one ring system of palau’amine. Recently, however, a series of reports questioned the originally proposed palau’amine structure and called for a revision of the stereochemistry of two carbon centers (iv). Now palau’amine has an identical chlorocyclopentane core with axinellamine (vi). With the target changed, we devised a new biomimetic pathway toward both natural products via a common intermediate (v), which was synthesized in 12 steps from the Diels-Alder adduct (iii).
15

Synthetic studies toward palau ne and enantioselective total synthesis of biogenetically related (+)-phakellin and (+)-monobromophakellin

Wang, Shaohui 15 May 2009 (has links)
Oroidin alkaloids, also known as pyrrole-imidazole alkaloids, have become a hot area of chemical and biological research due to their diverse and intriguing structural features and biological activities. Palau'amine (i), one of the hexacyclic oroidin-derived secondary metabolites, contains a fully substituted chloro-cyclopentane ring, a piperazinone moiety and two cyclic guanidines. With the uniqueness and complexity of its structure, palau’amine has been a synthetic challenge and has not yet succumbed to total synthesis. The overall objective of this work was to explore synthetic pathways toward palau’amine and biogenetically related congeners. Most of the work was focused on developing a synthetic pathway for the palau’amine structure proposed in its isolation report dated back to 1993. Starting from a Diels-Alder adduct (iii), oxidation/chlorination followed by phakellin (ii) annulation afforded an advanced pentacyclic intermediate possessing all the carbon framework and all but one ring system of palau’amine. Recently, however, a series of reports questioned the originally proposed palau’amine structure and called for a revision of the stereochemistry of two carbon centers (iv). Now palau’amine has an identical chlorocyclopentane core with axinellamine (vi). With the target changed, we devised a new biomimetic pathway toward both natural products via a common intermediate (v), which was synthesized in 12 steps from the Diels-Alder adduct (iii).
16

Synthetic Studies of Phenanthridines

Lin, Chao-hung 03 August 2005 (has links)
none
17

Synthetic Studies of Pyrrolophenanthridines

Chen, Xie-ying 12 June 2006 (has links)
The pyrrolophenanthridine class of alkaloids which have been isolated from various species of Amaryllidaceae.In intramolecular radicalcyclization, we used three methods to synthesize pyrrolophenanthridine.
18

Chemistry of diazonium tetraflouroborates : Studies on the enantioselective synthesis of lycorine

Rycroft, A. D. January 1988 (has links)
No description available.
19

Studies in the synthesis of piperidine alkaloids

Mosts, R. C. January 1987 (has links)
No description available.
20

Synthesis of pipecolic acid derivatives via aza-Diels-Alder reactions

Smith, Peter Duncan January 2000 (has links)
No description available.

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