- Facile access to cis-2,6-disubstituted tetrahydropyrans by palladium-catalyzed decarboxylative allylation: Total syntheses of (±)-Centrolobine and (+)-decytospolides A and B
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Cis-2,6-Tetrahydropyran is an important structural skeleton of bioactive natural products. A facile synthesis of cis-2,6-disubstituted-3,6-dihydropyrans as cis-2,6-tetrahydropyran precursors has been achieved in high regioand stereoselectivity with high yields. This reaction involves a palladium-catalyzed decarboxylative allylation of various 3,4-dihydro-2H-pyran substrates. Extending this reaction to 1,2-unsaturated carbohydrates allowed the achievement of challenging b-C-glycosylation. Based on this methodology, the total syntheses of (±)-centrolobine and (+)-decytospolides A and B were achieved in concise steps and overall high yields.
- Zeng, Jing,Tan, Yu Jia,Ma, Jimei,Leow, Min Li,Tirtorahardjo, Davin,Liu, Xue-Wei
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p. 405 - 409
(2014/04/03)
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- Synthesis, in vitro and in vivo cytotoxicity of 6,7-diaryl-2,3,8,8a-tetrahydroindolizin-5(1H)-ones
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A 6,7-diaryl-2,3,8,8a-tetrahydroindolizin-5(1H)-one library was constructed and tested against the colon cancer cell line HCT-116 as an initial screen for cytotoxic properties. Of this library, the parent compound, in which the southern aromatic ring remains unsubstituted, and the northern aromatic ring carries a 4-methoxy group, exhibited the most potent cytotoxicity with an IC50 value of 0.39 μM and displayed promising activity in vivo in the NCI's mouse hollow fiber assay.
- Kimball, F. Scott,Tunoori, Ashok Rao,Victory, Samuel F.,Dutta, Dinah,White, Jonathan M.,Himes, Richard H.,Georg, Gunda I.
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p. 4703 - 4707
(2008/02/12)
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- 1-[2-(4-Hydroxybenzoyl)ethanoyl]-2-piperidone and a process for production as well as alcohol fermentation promoter containing the same as effective ingredient
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The present invention relates to 1-[2-(4-hydroxybenzoyl)ethanoyl]-2-piperidone which is a novel compound of N-acyl lactam compounds and exhibit excellent effects in promoting fermentation in alcohol fermentation. This novel compound can be prepared by converting 2-(4-benzyloxybenzoyl)acetic acid into the acid chloride, then coupling the acid chloride with 2-piperidone or an alkylate of 2-piperidone and then subjecting to debenzylation.
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- Biosynthesis of Phenanthroindolizidine Alkaloids: Incorporation of 2-Pyrrolidin-2-ylacetophenone and Benzoylacetic Acid and Derivatives
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2-Pyrrolidin-2-ylacetophenone (12) and its oxygenated derivatives, (13) and (14), bearing 14C and 3H labels are synthesized and are shown to be intact precursors for the phenanthroindolizidine alkaloid, tylophorinine (16), in Tylophora asthmatica; the three amines, singly labelled with tritium, are shown to be precursors for tylophorine (3) and tylophorinidine (17).Benzoylacetic acid (9) and p-hydroxybenzoylacetic acid (10), but not 4-hydroxy-3-methoxybenzoylacetic acid, are also precursors for tylophorinine (16).The results allow partial description of the biosynthetic pathways tophenanthroindolizidine alkaloids.A degradation is described which allowed the location of label in 2-pyrrolidin-2-ylacetophenone, derived from ornithine, to be established.
- Herbert, Richard B.,Jackson, Frederick B.,Nicolson, Ian T.
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p. 825 - 831
(2007/10/02)
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