- Synthesis and in vivo evaluation of 3,4-disubstituted gababutins
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A range of 3,4-alkylated five-membered ring derivatives of gabapentin were synthesised. One compound (21) had an excellent level of potency against α2δ and was profiled in in vivo models of pain and anxiety.
- Blakemore, David C.,Bryans, Justin S.,Carnell, Pauline,Field, Mark J.,Kinsella, Natasha,Kinsora, Jack K.,Meltzer, Leonard T.,Osborne, Simon A.,Thompson, Lisa R.,Williams, Sophie C.
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scheme or table
p. 248 - 251
(2010/04/02)
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- Complete relative stereochemistry of maitotoxin
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By addressing the relative stereochemistry of the four acyclic portions via organic synthesis, the complete relative stereochemistry of maitotoxin (MTX) has been established as 1B. The relative stereochemistry of the C.1-C.15 portion was elucidated via a two-phase approach: (1) the synthesis of the eight diastereomers possible for model C, representing the C.1-C.11 portion, and the eight diastereomers possible for model D, representing the C.11-C.15 portion, and the comparison of their proton and carbon NMR characteristics with those of MTX, concluding that 9 and 35 represent the relative stereochemistry of the corresponding portions of MTX; (2) the synthesis of the two remote diastereomers 51 and 52, and comparison of their proton and carbon NMR characteristics with those of MTX, concluding that 51 represents the relative stereochemistry of the C.1-C.15 portion of MTX. The relative stereochemistry of the C.35-C.39, C.63-C.68, and C.134-C.142 acyclic portions was established via (1) the synthesis of the 8, 8, and 16 diastereomers possible for models E, F, and G, respectively, and (2) the comparison of their proton and carbon NMR characteristics with those of MTX, concluding that 81, 117, and 187, respectively, represent the relative stereochemistry of the corresponding portions of MTX. Some biogenetic considerations have been given to speculate on the absolute configuration of MTX. The vicinal proton coupling constants observed for models 51, 81, 117, and 187 were used to elucidate their preferred solution conformation. Assembling the preferred solution conformations found for the four acyclic portions allows one to suggest that the approximate global conformation of MTX is represented by the shape of a hook, with the C.35-C.39 portion being its curvature. MTX appears to be conformationally relatively rigid, except for conformational flexibility around the C.7-C.9 and C.12-C.14 portions. On the basis of the experimental results gained in the current work, coupled with those in the AAL-toxin/fumonisin area, it has been pointed out that the structural properties of 51, 81, 117, 187 and their diastereomers are inherent to the specific stereochemical arrangement of the small substituents on the carbon backbone and are independent from the rest of the molecule. Thus, it has been suggested that each of these diastereomers has the capacity to install a unique structural characteristic through a specific stereochemical arrangement of substituents on the carbon backbone, and that fatty acids and related classes of compounds may be able to carry specific information and serve as functional materials in addition to structural materials.
- Zheng,DeMattei,Wu,Duan,Cook,Oinuma,Kishi
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p. 7946 - 7968
(2007/10/03)
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- Cyclic Olefins by Anodic Oxidation of β-(Trimethylsilyl)carboxylic Acids. - β-(Trimethylsilyl)acrylic Acid Derivatives as Acetylene Equivalents in Diels-Alder Reactions
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Trimethylsilyl-substituted dienophiles 1, 2, and 4 react with dienes 6-14 in 66-100percent yields to give β-trimethylsilyl-substituted carboxylic acids 15-25, some of which are hydrogenated to 26-31.These are decarboxylated-desilylated to cyclic olefins 35-47 by Non-Kolbe electrolysis in 45-91percent yields.The dienophiles 1, 2, and 4 are thus suitable acetylene equivalents for Diels-Alder reactions.
- Hermeling, Dieter,Schaefer, Hans J.
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p. 1151 - 1158
(2007/10/02)
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- A Total Synthesis of (+/-)-Faranal, the True Trail Pheromone of Pharaoh's Ant, Monomorium pharaonis
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A relatively short total synthesis of the true trail pheromone of Pharaoh's ant, (+/-)-faranal is reported.The carbon skeleton was assembled by a Wittig condensation between (Z)-6-methyloct-5-en-2-one (4) and the 5-carboxypentylphosphonium salt (15).The ketone (4) was prepared in 'one-pot' and in a stereoselective manner using vinyl cuprate chemistry, while the relative stereochemistry of the two methyl substituents in the phosphonium salt (15) was established by using the Diels-Alder adduct (16) of buta-1,3-diene and maleic anhydride, which, after reduction and oxidative cleavage of the resulting cis-1,2-dimethylcyclohex-4-ene (18), gave only meso-3,4-dimethyladipic acid (19); this in turn was converted into the salt (15) in six straight-forward steps.
- Knight, David W.,Ojhara, Bol
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p. 955 - 960
(2007/10/02)
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- Stereoselective Total Synthesis of Racemic (3S,4R/3R,4S)- and a Diastereoisomeric Mixture of (6E,10Z)-3,4,7,11-Tetramethyltrideca-6,10-dienal (Faranal); The Trail Pheromone of the Pharaoh's Ant
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Racemic (3S,4R/3R,4S)-faranal has been synthesised by a convergent, stereospecific route which employed the addition of alkylcopper complexes to terminal acetylenes, to generate two trisubstituted double bonds, and a Diels-Alder reaction to establish the relative stereochemistry of the C-3, C-4 methyl groups.A diastereoisomeric mixture of faranals, enriched in the (3S,4S/3R,4R)-enantiomeric pair , has been synthesised by a somewhat shorter route via an intermediate diester, obtained from electrochemical dimerisation of ethyl crotonate.
- Baker, Raymond,Billington, David C.,Ekanayake, Neelakanthie
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p. 1387 - 1393
(2007/10/02)
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- Stereoselective Synthesis of (3R,4S/3S,4R)-(6E,10Z)-3,4,7,11-Tetramethyltrideca-6,10-dienal (Faranal); the Trail Pheromone of the Pharaoh's Ant
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Racemic (3R,4S/3S,4R)-faranal, has been synthesised by a convergent, stereospecific route from (1E,5Z)-1-iodo-2,6-dimethylocta-1,5-diene in good overall yield; this synthesis employed the addition of alkylcopper complexes to terminal acetylenes to generat
- Baker, Raymond,Billington, David C.,Ekanayake, Neela
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p. 1234 - 1235
(2007/10/02)
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