Der Übergang von Δ<sup>1</sup>‐Piperidein in Tetrahydro‐anabasin unter zellmöglichen Bedingungen

Schöpf, Clemens; Braun, Franz; Komzak, Alfred

doi:10.1002/cber.19560890805

Cited by 38 publications

(24 citation statements)

References 32 publications

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“…Indeed, Schöpf et al [10,11] have shown that the trimer 10 is stable at pH values above 12, whereas at pH values below 2 the monomer 9 is quickly formed. Moreover, they observed that ∆ 1 -piperideine dimerises to form tetrahydroanabasine (14), which may further react with a third molecule of 9 to generate trimer 13.…”

Section: Synthesis Of the Key Intermediates 8 And 11mentioning

confidence: 99%

Synthesis of New Analogues of the Tetraponerines

Rouchaud

Braekman

2009

Eur J Org Chem

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To evaluate the influences of the tetraponerine alkyl chains and tricyclic ring systems on their cytotoxic activities, we have prepared a series of alkyl derivatives (3a, 3b and 4a–f) of the non‐natural tricyclic skeletons decahydro‐2H,6H‐dipyrido[1,2‐a:1′,2′‐c]pyrimidine (3, 6–6–6 skeleton) and dodecahydro‐2H‐1,8a‐diazaphenanthrene (4, iso‐6–6–6 skeleton). In this study, two ways to synthesise the 6–6–6 analogues have been developed and compared. One is based on the condensation of α‐tripiperideine with diethyl malonate (DEM) in water at pH 11. This yielded oxo ester 11, precursor of the amino nitrile 8, but only in moderate yield. In the second pathway, the key intermediate 8 was more efficiently synthesised by starting from 2‐(2‐piperidyl)ethanol. Treatment of 8 with alkyl Grignard reagents led to the 6–6–6 analogues 3a and 3b. When the one‐pot reaction between α‐tripiperideine and DEM was performed in water at pH 8, the lactam 12, precursor of the iso‐6–6–6 skeleton, was obtained in a yield of 76 %. The same lactam was also obtained in a yield of 86 % by treatment of tetrahydroanabasine 14 with DEM in water at pH 8. Lactam 12 was transformed into the iso‐6–6–6 analogues 4a–4f. The cytotoxic activities of the 6–6–6 and iso‐6–6–6 analogues against HT29 cancer cells were compared with those of the 5–6–5 and 6–6–5 tetraponerines and with those of solenopsin analogues. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

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Section: Synthesis Of the Key Intermediates 8 And 11mentioning

confidence: 99%

Synthesis of New Analogues of the Tetraponerines

Rouchaud

Braekman

2009

Eur J Org Chem

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“…Many variations are possible for a route leading to matrine from a Clo unit, tetrahydroanabasine (13), and a C, unit, A'-piperideine (5), which are consistent with model A (Scheme 3). Three of these variations are outlined in Scheme 4.…”

Section: The Biosynthesis Of Matrinementioning

confidence: 74%

“…In aqueous solution at pH 6-8, A'-piperideine dimerizes readily and within a few hours 80-90% of the compound has been converted into dimer (13 of the dimer have the same molar specific activity, i.e. each of the labelled carbon atoms contains 50% of the activity of the intact molecule.…”

Section: The Biosynthesis Of Matrinementioning

confidence: 99%

Biosynthesis of the quinolizidine alkaloids. Incorporation of Δ¹-piperideine into matrine

Leeper¹,

Grue-Sørensen²,

Spenser³

1981

Can. J. Chem.

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Label from [6-14C]-Δ1-piperideine is incorporated nonrandomly into the carbon skeleton of the quinolizidine alkaloid, matrine, in Sophora tetraptera and S. microphylla. The distribution of radioactivity was determined by a new chemical degradation sequence. On the basis of the results, one of two previously postulated biogenetic schemes must be discarded. A modified biogenetic scheme is presented which is consistent with the present results and also leads to the correct stereochemistry of matrine.

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“…This can be best appreciated in the work of Schçpf who investigated the formation of tetrahydroanabasin (26) from tetrahydropyridine 25. [22] In line with these studies, the large number of the stable isolable cyclic imines possess a,a-disubstitution; precluding the formation of the corresponding enamine and subsequent oligomerisation.…”

Section: Introductionmentioning

confidence: 77%

Synthesis of (±)‐Strychnofoline via a Highly Convergent Selective Annulation Reaction

Lerchner¹,

Carreira²

2006

Chemistry A European J

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Studies aimed at preparing (+/-)-strychnofoline by total synthesis are detailed. The route described makes use of a recently developed MgI(2)-mediated ring-expansion reaction of spiro[cyclopropan-1,3'-oxindole] with a cyclic disubstituted aldimine. The ring-expansion product was formed as a single diastereoisomer in 55 % yield, possessing the same stereochemical pattern found in strychnofoline. In addition, our synthetic effort has led to the development of new reaction methodology to access 3,4-disubstituted cyclic aldimines.

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Der Übergang von Δ¹‐Piperidein in Tetrahydro‐anabasin unter zellmöglichen Bedingungen

Cited by 38 publications

References 32 publications

Synthesis of New Analogues of the Tetraponerines

Synthesis of New Analogues of the Tetraponerines

Biosynthesis of the quinolizidine alkaloids. Incorporation of Δ¹-piperideine into matrine

Synthesis of (±)‐Strychnofoline via a Highly Convergent Selective Annulation Reaction

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Der Übergang von Δ1‐Piperidein in Tetrahydro‐anabasin unter zellmöglichen Bedingungen

Cited by 38 publications

References 32 publications

Synthesis of New Analogues of the Tetraponerines

Synthesis of New Analogues of the Tetraponerines

Biosynthesis of the quinolizidine alkaloids. Incorporation of Δ1-piperideine into matrine

Synthesis of (±)‐Strychnofoline via a Highly Convergent Selective Annulation Reaction

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Der Übergang von Δ¹‐Piperidein in Tetrahydro‐anabasin unter zellmöglichen Bedingungen

Biosynthesis of the quinolizidine alkaloids. Incorporation of Δ¹-piperideine into matrine