Synthesis of the Cyclostellettamines A−F and Related Bis(3-alkylpyridinium) Macrocycles

Wanner, Martin J.; Koomen, Gerrit‐Jan

doi:10.1002/(sici)1099-0690(199805)1998:5<889::aid-ejoc889>3.0.co;2-g

Cited by 17 publications

(5 citation statements)

References 15 publications

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“…His group also reported a biomimetic synthesis in which coupling was achieved via a pyridine ring formation [34]. Olefin metathesis as applied by Balando and co-workers [35] and the optimized synthesis with other strategies of protection and deprotection [36] open further avenues for the generation of pyridinium macrocycles.…”

Section: Synthesismentioning

confidence: 99%

Synthesis of 3-Alkyl Pyridinium Alkaloids from the Arctic Sponge Haliclona viscosa

2010

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3-Alkyl pyridinium alkaloids (3-APAs) are common secondary metabolites in marine sponges of the order Haplosclerida. In recent years, our laboratory has isolated and synthesized several new members of this family such as haliclamines C–F, viscosamine, viscosaline and a cyclic monomer. All of them were isolated from the Arctic sponge Haliclona viscosa collected in Spitsbergen, Norway. In this article we report the syntheses of these secondary metabolites from Haliclona viscosa and related compounds and give a short overview of the bioactivity.

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Section: Synthesismentioning

confidence: 99%

Synthesis of 3-Alkyl Pyridinium Alkaloids from the Arctic Sponge Haliclona viscosa

2010

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“…(7). Starting from acrolein the corresponding non-isolated phosphonium salt 35 [51] reacted via a Wittig reaction with 2-hydroxybenzaldehyde and formed (Z)-36. The cyclization reaction using boron trifluoride diethyl etherate in diethyl ether as a solvent during six days gave 2-methoxy-2,3-dihydrobenzoxepin 37.…”

Section: B)mentioning

confidence: 99%

New Medium Oxacyclic O,N-Acetals and Related Open Analogues: Biological Activities

Campos

Saniger²,

Marchal³

et al. 2005

CMC

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Attention is increasingly being focussed on the cell cycle and apoptosis as potential targets for therapeutic intervention in cancer. Taking 1-[(2-oxepanyl)]-5-fluorouracil previously prepared by us, we committed ourselves to increase the lipophilicity of this upper cyclohomologue of Ftorafur and prepared a series of bioisosteric benzannelated seven-membered 5-FU O,N-acetals to test them against the MCF-7 human breast cancer cell line. Benzo-fused seven-membered O,O-acetals or their acyclic analogues led to the expected 5-FU O,N-acetals (or aminals), in addition to six- and to 14-membered aminal structures and acyclic compounds. All the cyclic aminals provoked a G(o)/G(1)-phase cell cycle arrest, whereas Ftorafur, a known prodrug of 5-FU, and 1-[2-(2-hydroxymethyl-4-nitrophenoxy)-1-methoxyethyl]-5-fluorouracil (51) induced an S-phase cell cycle arrest. Although breast cancer is most often treated with conventional cytotoxic agents it has proved difficult to induce apoptosis in breast cancer cells and, consequently, improved clinical responses may be obtained by identifying therapies that are particularly effective in activating apoptosis. 1-(2,3-Dihydrobenzoxepin-2-yl)-5-fluorouracil (26) may be particularly useful in stimulating apoptosis in breast cancer. This compound is more potent as an apoptotic inductor than paclitaxel (Taxol). Finally, a fact that is worth emphasizing is that the cyclic and acyclic 5-FU O,N-acetals induce neither toxicity nor death in mice after one month's treatment when administered intravenously twice a week, with a 50 mg/kg dose each time. Taken together, the experimental findings provide evidence of specific anti-tumour activity of these new substances and warrant further evaluation in in vivo models of breast cancer to future clinical applications.

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“…The key reaction of this approach is Pictet-Spengler condensation of tryptamine (5) with tricarbonyl substituted imidazole (21). Condensation of 18 with the stabilised phosphorane (19) 19 yielded crystalline ylide (20). 17 Vicinal tricarbonyl substituted N-methylimidazole (21) was prepared from N-methyl-5imidazolecarboxylic acid (17).…”

Section: Synthesis Of Xestomanzamine Bmentioning

confidence: 99%

“…A convenient large scale synthesis of the corresponding methyl ester has been described; 18 hydrolysis of the methyl ester and reaction of acid (17) with oxalyl chloride afforded the acid chloride (18). The intermediate (23) was oxidised in situ by air-oxygen to give the final product xestomanzamine B (2) in a yield of 43% starting from ylide (20). Ozonolysis of 20 in a mixture of dichloromethane and methanol followed by reductive work-up furnished the vicinal tricarbonyl derivative (21), which was used without further purification in the condensation step with tryptamine (5).…”

Section: Synthesis Of Xestomanzamine Bmentioning

confidence: 99%

Synthesis of Xestomanzamines A and B

Burm¹,

Jongmans²,

Kampen³

et al. 2001

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Synthetic pathways are described for the synthesis of two naturally occurring β-carbolines, xestomanzamine A and B. The synthesis of aromatic xestomanzamine A was most conveniently achieved by way of a Grignard reaction in dichloromethane. This route is suitable for the synthesis of analogues with modifications in the imidazole ring of xestomanzamine A. Xestomanzamine B, an oxidation-sensitive dihydro-β-carboline, was prepared by Pictet-Spengler condensation of tryptamine with a vicinal tricarbonyl substituted imidazole. # Present address:

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Synthesis of the Cyclostellettamines A−F and Related Bis(3-alkylpyridinium) Macrocycles

Cited by 17 publications

References 15 publications

Synthesis of 3-Alkyl Pyridinium Alkaloids from the Arctic Sponge Haliclona viscosa

Synthesis of 3-Alkyl Pyridinium Alkaloids from the Arctic Sponge Haliclona viscosa

New Medium Oxacyclic O,N-Acetals and Related Open Analogues: Biological Activities

Synthesis of Xestomanzamines A and B

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