17585-59-0Relevant articles and documents
A comparative study of two polymorphs of l-aspartic acid hydrochloride
Benali-Cherif, Rim,Takouachet, Radhwane,Bendeif, El-Eulmi,Benali-Cherif, Nourredine
, p. 689 - 692 (2014)
Two polymorphs of l-aspartic acid hydrochloride, C4H 8NO4+ Cl-, were obtained from the same aqueous solution. Their crystal structures have been determined from single-crystal data collected at 100 K. The crystal structures revealed three- and two-dimensional hydrogen-bonding networks for the triclinic and orthorhombic polymorphs, respectively. The cations and anions are connected to one another via N-H...Cl and O-H...Cl interactions and form alternating cation-anion layer-like structures. The two polymorphs share common structural features; however, the conformations of the l-aspartate cations and the crystal packings are different. Furthermore, the molecular packing of the orthorhombic polymorph contains more interesting interactions which seems to be a favourable factor for more efficient charge transfer within the crystal.
3-Triphenylphosphonio-2,5-piperazinediones as new chiral glycine cation equivalents
Gorewoda, Tadeusz,Mazurkiewicz, Roman,Simka, Wojciech,Mloston, Grzegorz,Schroeder, Grzegorz,Kubicki, MacIej,Kuznik, Nikodem
experimental part, p. 823 - 833 (2011/09/12)
3-Triphenylphosphonio-2,5-piperazinediones were effectively synthesized from homochiral valine or proline via Boc-Val-Gly-OMe, Boc-Pro-Gly-OMe or Cbz-Pro-Gly-OMe. Retention of configuration of the primary stereogenic center of the valine and proline moieties was observed. Diastereoselective nucleophilic substitution of the triphenylphosphonium group in 2,5-piperazinediones with S-, N-, P- and C-nucleophiles was observed. The configuration of the substitution products was assigned either by their hydrolysis and decarboxylation or based on the analysis of the H-C(3)-N-H coupling constants of 3-substituted-2,5- piperazinediones derived from proline. The trans-stereoselectivity was predominant in reactions of 3-triphenylphosphonio-1,6-trimethylene-2,5- piperazinediones with the nucleophiles investigated. The stereodifferentiating ability of the proline moiety is much stronger than that of the valine unit and allowed nucleophilic α-functionalization of the glycine moiety with good to excellent diastereoselectivity.
Amino acid esters of phenols as prodrugs: Synthesis and stability of glycine, β-aspartic acid, and α-aspartic acid esters of p-acetamidophenol
Kovach,Pitman,Higuchi
, p. 881 - 885 (2007/10/02)
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