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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.
21

Routes to chiral N-acyliminium ion precursors for the synthesis of optically active pure ring-fused pyrroloisoquinoline alkaloids

James, Stella L. January 2003 (has links)
Pyrrolisoquinoline (B) is found as a major structural motif of the erythrina alkaloid group of natural products. We recognised that a suitably substituted bicyclic lactam (A) could act as a precursor in an intramolecular N-acyliminium mediated cyclisation reaction in a stereoselective approach to the core of the erythrinane target ring system.
22

The synthesis of (±)-anatoxin-a

Vernon, Peter G. January 1988 (has links)
No description available.
23

An enantioselective synthesis of substituted 1,2,3,4,5,6-hexahydro-2,6-methano-3-benzazocines

Williams, Colin Stephen January 1990 (has links)
No description available.
24

Studies towards the total synthesis of strychnine

McGowan, Amanda Dawn January 2000 (has links)
No description available.
25

Synthetic Studies of Amaryllidaceae Alkaloids

Chen, Zong-yi 31 May 2007 (has links)
The Amaryllidaceae class of alkaloids have been isolated from various species of Amaryllidaceae. In intramolecular radical cyclization, we used three methods to synthesize Amaryllidaceae.
26

Synthetic and mechanistic studies in free radical..

Callaghan, Owen January 1999 (has links)
No description available.
27

Use of Imines and Iminium Salts in Alkaloid Synthesis

Jahangir 12 1900 (has links)
The usefulness of imines and iminium salts in the convergent synthesis of alkaloids and their synthetic analogues is described. Thus the anion derived from [3,4-c]pyridin-3[1H]-one, by treatment with LDA (lithium diisopropylamide) or LHS, (lithium bis-trimethylsilylamide) reacts with 2-methyl-3, 4-dihydro- isoquinolinium salts yielding aza analogues of phthalideisoquinoline alkaloids. The condensation of the same anion with 3,4-dihydroisoquinolines has provided, in a single step, azaprotoberberines containing the benzo[a)pyrido[3,4-g]quinolizine structure found in a number of Alangium alkaloids. The reaction of methyllithium with oxoberberine as a means of introducing a methyl group C-8 is described. The resulting iminium salt was reduced to a mixture of racemic a- and B-8-methylcanadines. This reaction has been applied to the synthesis of the Alangium alkaloid (+/-)-alamaridine. Condensation of lithium salts of 3-cyano-4-methylpyridine and 3-cyano-4-methyl-5-vinylpyridine with a complex of 3 ,4-dihydroisoquinolines and trimethylsilyl trifluoromethanesulphonate has been studied. The amidines formed as condensation products were transformed by hydrolysis into 5,6,13,14-tetrahydro-8H-isoquino[2,1-b][2,7]-naphthyridin-8-ones, a ring system found in several alkaloids of Alangtum lamarckii. These reactions have been employed in the synthesis of the Alangium alkaloids, (±)-alangimaridine and alangimarine. The usefulness of this reaction has been further demonstrated in the synthesis of N-benzyl derivatives of 3,14-dihydronauclefine and 3,14-dihydroangustine containing 8,13,13b,14-tetrahydroindolo[2•,3•:3,4]pyrido[1,2-b][2,7]-naphthyridin- 5[7H]-one. / Thesis / Doctor of Philosophy (PhD)
28

The Structure of Lycopodine

Harrison, William Ashley 09 1900 (has links)
A study has been made of the chemistry of lycopodine, the major alkaloid of several species of Lycopodium. From the information obtained, most of the peripheral structure of the lycopodine molecule can be deduced. A complete structure is proposed for the alkaloid. / Thesis / Doctor of Philosophy (PhD)
29

Izolace alkaloidů z prameničky obecné (Fontinalis antipyretica Hedw.) / Alkaloid isolation from Fontinalis antipyretica Hedw.

Malá, Marie January 2012 (has links)
Marie Malá, Isolation of alkaloids from Fontinalis antipyretica, thesis, Charles University in Prague, Faculty Of Pharmacy in Hradec Králové, 2012, 55 pages. The thesis Isolation of alkaloids from Fontinalis antipyretica, deals with quantification and isolation of substances of alkaloid character from above mentioned moss. The plant material collected in different localities in Czech Republic was extracted with methanol. The extract was subesquently used for isolation of alkaloids by HPLC method. The obtained amount of β-Carboline alkaloid was 2,4mg. The results of HPLC analysis (retention time, spectrum) of this sample were compared to harmalol standard and found the same. Finally the H NMR analysis proved, that the substance obtained by this experiment is not harmalol, but someother β-Carboline alkaloid.
30

Obsah alkaloidů a flavonoidů v prameničce obecné / Alkaloid and flavonoid content in Fontinalis antipyretica Hedw.

Ptáčníková, Lucie January 2012 (has links)
Lucie Ptáčníková, The volume of alkaloids and flavonoids in Fontinalis antipyretica, Thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, thesis tutor: PharmDr. Jan Martin, PhD., Hradec Králové, 2012, 55 pages. Thesis called "Content of alkaloids and flavonoids in Fontinalis anitpyretica" establishes alkaloids and flavonoids and identifies one substance of these alkaloids in the above-mentioned water moss. The main purpose of this thesis was to obtain samples of Fontinalis antipyretica from selected locations in the Czech Republic (Ledce, Rychnovek, Kunvald). Next purpose was to determine alkaloids and flavonoids of collected material, isolated one substance of alkaloid character and verify identity of selected alkaloid. The content of alkaloids and flavonoids was determined by using the high-performance liquid chromatography (HPLC). The results show that β - carboline alkaloid harmin was determined by consensus UV spectrum and retention time with standard. Consequently flavonoids called myricetin and hyperosid was determined. Identity of β - carboline alkaloid harmin was verified by using NMR analysis. Keywords: alkaloids - harmalol - harmin - Fontinalis antipyretica - flavonoids

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