- Diastereofacial Selectivity in Reduction of Chiral Tetramic Acids
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The reduction of (5S)-5-alkyl-2,4-dioxopyrrolidines, so-called tetramic acids, by NaBH4 gives only partial diastereofacial selectivity in the case of the N-substituted analogues 9f-i, unlike the carbamate derivatives 9a-e which give the reduced cis-pyrrolidinones 10βa-e.Increasing the steric hindrance of either the N- or C-5-substituents enhances the re-face selectivity.On the other hand, reduction of the heterobicyclic compound 9n leads to a dramatic reversal of the stereoselectivity.Preliminary calculations show that the N-atom of the ring is slightlypyramidalized; the direction of hydride addition could be a consequence of this finding.
- Galeotti, Nathalie,Poncet, Joeel,Chiche, Laurent,Jouin, Patrick
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- Bioactivity and Mode of Action of Bacterial Tetramic Acids
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Microbially produced 3-acyltetramic acids display a diverse range of biological activities. The pyreudiones are new members of this class that were isolated from bacteria of the genus Pseudomonas. Here, we performed a structure-activity relationship study
- Klapper, Martin,Paschold, André,Zhang, Shuaibing,Weigel, Christiane,Dahse, Hans-Martin,G?tze, Sebastian,Pace, Simona,K?nig, Stefanie,Rao, Zhigang,Reimer, Lisa,Werz, Oliver,Stallforth, Pierre
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- Expanding the scope of oligo-pyrrolinone-pyrrolidines as protein-protein interface mimics
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Oligo-pyrrolinone-pyrrolidines (generic structure 1) have the potential to interfere with protein-protein interactions (PPIs), but to reduce this to practice it is necessary to be able to synthesize these structures with a variety of different side chains
- Raghuraman, Arjun,Xin, Dongyue,Perez, Lisa M.,Burgess, Kevin
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p. 4823 - 4833
(2013/07/05)
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- A synthetic approach to diverse 3-acyltetramic acids via O- to C-acyl rearrangement and application to the total synthesis of penicillenol series
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For the efficient approach to medicinally important α-branched 3-acyltetramic acids, the key reaction of O- to C- acyl rearrangement using α-amino-acid-derived 4-O-acyltetramic acids was extensively examined in the presence of various metal salts. Use of
- Sengoku, Tetsuya,Nagae, Yuta,Ujihara, Yasuaki,Takahashi, Masaki,Yoda, Hidemi
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p. 4391 - 4401
(2012/06/18)
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- Pyrrolinone-pyrrolidine oligomers as universal peptidomimetics
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Peptidomimetics 1-3 were prepared from amino acid-derived tetramic acids 7 as the key starting materials. Calculations show that preferred conformations of 1 can align their side-chain vectors with amino acids in common secondary structures more effectively than conformations of 3. A good fit was found for a preferred conformation of 2 (an extended derivative of 1) with a sheet/β-turn/sheet motif.
- Raghuraman, Arjun,Ko, Eunhwa,Perez, Lisa M.,Ioerger, Thomas R.,Burgess, Kevin
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supporting information; experimental part
p. 12350 - 12353
(2011/10/02)
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- Dipeptide analogues containing 4-ethoxy-3-pyrrolin-2-ones
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Pyrrolidine-2,4-diones (1) are naturally occurring analogues of amino acids. We herein present a facile synthesis of N-acylated, O-alkylated pyrrolin-2-ones (2) in high yield and excellent enantiopurity. Molecular mechanics calculations suggest that the r
- Hosseini, Masood,Kringelum, Henriette,Murray, Anthony,Tonder, Janne E.
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p. 2103 - 2106
(2007/10/03)
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- Mirabimide E, an unusual N-acylpyrrolinone from the blue-green alga Scytonema mirabile: Structure determination and synthesis
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Mirabimide E, a solid tumor selective cytotoxin from the terrestrial blue-green alga Scytonema mirabile UH strain BY-8-1, possesses an unprecedented tetrachlorinated ethylene group and has been identified as (5S,2'R,3'R)N-(anti-8',8',9',9'-tetrachloro-3'-(carbamoyloxy)-2'-methy ldecanoyl)-4-methoxy-5-methyl-3-pyrrolin-2-one. The total structure, including absolute stereochemistry, of this novel N-acylpyrrolinone was concluded from a combination of spectral and chemical studies, including stereoselective syntheses of three degradation products, viz. methyl (2R,3R)anti-8,8,9,9-tetrachloro-3-hydroxy-2-methyldecanoate, (5R,6R)-trans-5-methyl-6-(5,5',6,6'-tetrachloroheptyl)-1-oxa-3-azacycl ohexane-2,4-dione, and (5S)-4-methoxy-5-methyl-3-pyrrolin-2-one, and the total synthesis of mirabimide E itself. The influence of the carbamate ester group on the chemical degradation and synthesis of mirabimide E is described.
- Paik, Seunguk,Carmeli, Shmuel,Cullingham, Jean,Moore, Richard E.,Patterson, Gregory M. L.,Tius, Marcus A.
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p. 8116 - 8125
(2007/10/02)
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