- PROCESS FOR CONVERTING LUPANINE INTO SPARTEINE
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The present invention relates to processes for preparing enantiopure Lupanine and Sparteine.
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Page/Page column 6; 7
(2014/12/12)
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- Oxidative deamination of tetrahydroanabasine with o-quinones: An easy entry to lupinine, sparteine, and anabasine
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A mild oxidative deamination reaction of tetrahydroanabasine O-methyloxime 17 is described, making use of an o-quinone that is based on topaquinone (TPQ, 11), the cofactor that is present in copper-containing amine oxidases. In situ ring closure of the oxidation product produced double functionalized quinolizidine 5, containing an enamine functionality with excellent reactivity. From this quinolizidine 5 a variety of biogenetically related lupin alkaloids were prepared: lupinine (7) and aminolupinane (8) via reductive sequences and sparteine (9) via a condensation reaction with dehydropiperidine 1. The configurationally more favorable trans isomers epilupinine (25) and β-isosparteine (10) were formed when more drastic reaction conditions were used for oxime hydrolysis. Anabasine (4) and a new 5-piperidylanabasine derivative 6 were formed by an unexpected acid catalyzed ring transformation reaction, whereby the pyridine ring was formed via oxime-induced aromatization. The stereochemistry of the reaction products and the biogenetic implications are discussed.
- Wanner, Martin J.,Koomen, Gerrit-Jan
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p. 5581 - 5586
(2007/10/03)
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- Synthesis of Cadaverine and its Incorporation into five Quinolizidine Alkaloids
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Cadaverine dihydrochloride (13) was synthesised by the sequential introduction of two equivalents of sodium cyanide to a C3 precursor, and it was fed to Lupinus luteus and L. polyphyllus plants.Complete labelling patterns were obtained in five quinolizidine alkaloids by 13C n.m.r. spectroscopy.The 13C-13C doublets observed in the spectra of (-)-lupinine (3), (-)-sparteine (4), (+)-lupanine (5), (+)-13α-hydroxylupanine (6), and (+)-angustifoline (7) derived biosynthetically from the doubly labelled precursor (13) confirm the intact, specific incorporation of two cadaverine units into the tetracyclic quinolizidine alkaloid skeletons.The cadaverine (13) units are incorporated to about the same extent into each part of the quinolizidine alkaloids (3)-(7).Two of the 13C chemical shifts for lupanine (5) have been reassigned.The labelling pattern of the tricyclic alkaloid angustifoline (7) indicates that the allyl group originates by degradation of one ring of a tetracyclic precursor.
- Robins, David J.,Sheldrake, Gary N.
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p. 2101 - 2120
(2007/10/02)
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