- Asymmetric synthesis of 4-substituted prolines as conformationally constrained amino acid analogues
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Treatment of readily available chiral building block 1 with (2R)-2,3-O- isopropylideneglyceraldehyde (5) provides a new route for asymmetric synthesis of 2,4-disubstituted pyrrolidines. Several proline-amino acid chimeras: proline-leucine, proline-lysine, proline-arginine and proline- glutamic acid, are synthesized in highly diastereomerically pure forms.
- Wang, Qian,Sasaki, N. Andre,Potier, Pierre
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p. 15759 - 15780
(2007/10/03)
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- Asymmetric synthesis of 2,4-disubstituted pyrrolidines
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A new strategy for asymmetric synthesis of 2,4-disubstituted pyrrolidines is described, starting from readily available chiral building blocks 1 and (2R)-2,3-O-isopropylideneglycealdehyde (6).
- Wang, Qian,Sasaki, N. Andre,Potier, Pierre
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p. 5755 - 5758
(2007/10/03)
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- Stereospecific synthesis of cis-2,4-pyrrolidinedicarboxylic acid and cis-2,5-piperidinedicarboxylic acid
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Lactams derived from hetero Diels-Alder adducts were stereospecifically converted into cis-2,4-pyrrolidinedicarboxylic acid and cis-2,5- piperidinedicarboxylic acid by ruthenium tetroxide oxidation. Optically active (2S,4S)-(-)-2,4-pyrrolidinedicarboxylic acid and (2R,4R)-(+)-2,4- pyrrolidinedicarboxylic acid were synthesized from (1S,4R)-(+)-2- azabicyclo[2.2.1]hept-5-en-3-one and (1R,4S)-(-)-2-azabicyclo[2.2.1]hept-5- en-3-one, respectively.
- Arakawa, Yasushi,Yasuda, Mika,Ohnishi, Masafumi,Yoshifuji, Shigeyuki
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p. 255 - 259
(2007/10/03)
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- An enantioselective route to pyrrolidines: Removal of the chiral template from homochiral pyrroloimidazoles
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Two-step reductive removal of the chiral template from optically active pyrroloimidazoles, available from 1,3-dipolar cycloaddition of homochiral imidazolinium ylides, gives optically active substituted pyrrolidines. Selective manipulation of the substituents affords, e.g. naturally occurring proline derivatives and homochiral pyrrolizidines.
- Jones, Raymond C. F.,Howard, Kevin J.,Snaith, John S.
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p. 1711 - 1714
(2007/10/03)
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- Synthesis of two cyclic analogs of glutamic acid: cis- and trans-pyrrolidine-2,4-dicarboxylic acids
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The tosyl ester 2 of tetraethyl 1-acetamido-4-hydroxybutane- 1,1,3,3-tetracarboxylate gave 4-methylene glutammic acid in 90% yield by refluxing with concentrated HC1. Treatment of 2 with NaOEt, then with refluxing concentrated HC1 gave a 54% yield of cis
- Trigalo, Franois,Molliex, Christophe,Champion, Brigitte,Azerad, Robert
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p. 3049 - 3050
(2007/10/19)
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- Conformationally Defined Neurotransmitter Analogues. Selective Inhibition of Glutamate Uptake by One Pyrrolidine-2,4-dicarboxylate Diastereomer
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In order to determine the conformational requirements for binding of L-glutamate to the proteins involved in the process of neurotransmission, rigid analogues containing an embedded glutamate moiety have been prepared.These "conformer mimics", the pyrrolidine-2,4-dicarboxylates 4, 7, 11, and 14, were synthesized from commercially available trans-4-hydroxy-L-proline and cis-4-hydroxy-D-proline, and then were tested for their ability to inhibit the high-affinity transport of -L-glutamate into synaptosomes and to block the binding of radioligands to the NMDA (N-methyl-D-aspartate), KA (kainate), and QA (quisqualate) glutamate neurotransmitter receptor sites.While none of the four analogues binds effectively to the excitatory receptors, the L-trans-isomer 7 is a potent and selective competitive inhibitor of L-glutamate transport.These results delineate a specific structural/conformational preference for binding to the uptake system that is distinct from that required for binding to the NMDA, KA, and QA receptors.
- Bridges, Richard J.,Stanley, Mark S.,Anderson, Michael W.,Cotman, Carl W.,Chamberlin, A. Richard
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p. 717 - 725
(2007/10/02)
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