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Synthesis and Molecular Structure of Chiral (2S, 5S)-tert-Butyl 3-Oxo-2-oxa-5-azabicyclo[2.2.2]octane-5-carboxylate  [PDF]
Tetsuji Moriguchi,Suvratha Krishnamurthy,Toru Arai,Akihiko Tsuge
Journal of Crystallography , 2014, DOI: 10.1155/2014/150796
Abstract: The title compound (2S, 5S)-tert-butyl 3-oxo-2-oxa-5-azabicyclo[2.2.2]octane-5-carboxylate was synthesized as a chiral cyclic amino acid ester from the corresponding cis- and trans-5-hydroxypipecolic acid ethyl esters via an intramolecular lactonization reaction without using chiral catalyst or enzyme and without separation by chiral column chromatography. The chiral compound was characterized using 1H NMR spectroscopy and high-resolution mass spectrometry. Its exact structure was then determined via single crystal X-ray diffraction analysis of a single crystal obtained after recrystallization of the compound from ethyl acetate/diethyl ether. The crystal was found to be of the orthorhombic space group P212121 (No. 19, noncentrosymmetric, chiral) with ??, ??, ??, 4?g/cm3, and a Flack parameter of 0.0(5) at 90?K. The compound has a bicyclo[2.2.2]octane structure comprised of lactone and piperidine groups. 1. Introduction Hydroxypipecolic acid (5-hydroxy-2-piperidinecarboxylic acid) is a six-membered homologue of 4-hydroxyproline found in some natural plants, such as date and acacia trees, whereas 4-hydroxyproline is found in animals (collagen) [1, 2]. Several hydroxypipecolic acid derivatives have been synthesized via intramolecular reactions of precursors functionalized with epoxide groups [3–5]. However, a diastereomeric mixture of cis- and trans-5-hydroxymethylpipecolic acids has generally been obtained, and in some cases, the formation of undesired 5-hydroxymethylprolines has also been noted [4–6]. Because the intramolecular reaction of epoxide precursors suffers from the formation of stereo- and regioisomers, a straightforward method for the preparation, isolation, and characterization of the pure single enantiomers of hydroxypipecolic acid and derivatives of this rare amino acid is required. Previously, we synthesized a 4-hydroxyproline derivative from an amino acid bearing an epoxide [7]. During this study, we observed that the cis isomer underwent intramolecular lactonization. In addition, we reported the crystal structure of “racemic” tert-butyl 3-oxo-2-oxa-5-azabicyclo[2.2.1]heptane-5-carboxylate prepared using an alternative synthetic pathway [8]. Based on these previous results, it was expected that cis-5-hydroxypipecolic acids would also undergo intramolecular lactonization, while the corresponding trans isomers would not. Indeed, when a mixture of a cis- and trans-5-hydroxypipecolic acid derivative was reacted under acidic conditions, the cis isomer was successfully converted to the lactone (2S, 5S)-tert-butyl
Al2O3 coated with 3-n-propyl-1-azonia-4-azabicyclo[2.2.2]octane silsesquioxane chloride and its use for immobilization of cobalt(II) tetrasulfonated phthalocyanine in oxalic acid electrooxidation
Ramos, André R.;Arguello, Jacqueline;Magosso, Hérica A.;Gushikem, Yoshitaka;
Journal of the Brazilian Chemical Society , 2008, DOI: 10.1590/S0103-50532008000400020
Abstract: a water-soluble polymer prepared by sol-gel process, 3-n-propyl-1-azonia-4-azabicyclo[2.2.2]octane silsesquioxane chloride, was adsorbed on alumina surface. this polymer-coated alumina was able to effectively immobilize cobalt(ii) tetrasulfonated phthalocyanine complexes as counter ions. cobalt phthalocyanine immobilized in this way is well and tightly adsorbed on al2o3/3-n-propyl-1-azonia-4-azabicyclo[2.2.2]octane silsesquioxane chloride surface. furthermore, when incorporated to a carbon paste electrode showed a good electrocatalytic response toward the acid oxalic oxidation, making it a suitable electrode material. a linear relationship (r = 0.998) between the current responses obtained by chronoamperometric measurements and the oxalic acid concentration in the range of 7.4 × 10-5 - 9.1 × 10-4 mol l-1 was observed. a detection limit of 18 μmol l-1 was also determined.
1,4-Diazabicyclo[2.2.2]octane (DABCO) 5-aminotetrazolates  [PDF]
Gerhard Laus,Volker Kahlenberg,Klaus Wurst,Michael Hummel,Herwig Schottenberger
Crystals , 2012, DOI: 10.3390/cryst2010096
Abstract: The crystal structures of four salts of 1,4-diazabicyclo[2.2.2]octane (DABCO) and 5-aminotetrazole are described. Anhydrous 1:1 ( Pbca, R gt = 0.041) and 1:2 ( P, R gt = 0.038) salts form hydrogen-bonded layers of anions and cations. The monohydrate of the 1:1 compound ( P2 1/ c, R gt = 0.038) shows infinite chains of DABCO cations and an undulated layer of anions and water molecules. The octahydrate of the 3:2 compound ( P2 1/ c, R gt = 0.042) features DABCO triples and clusters of four tetrazolate ions in a network of water molecules.
5-Amino-3-ethoxy-1,8,8-trimethyl-2-azabicyclo[2.2.2]octa-2,5-diene-4,6-dicarbonitrile  [cached]
Suchada Chantrapromma,Thitipone Suwunwong,Pumsak Ruanwas,Nawong Boonnak
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812032990
Abstract: The title 2-azabicyclo[2.2.2]octa-2,5-diene derivative, C14H18N4O, crystallized out with two independent molecules with similar conformations in the asymmetric unit. In each molecule, the three six-membered rings adopt boat conformations. The molecules exist in the enamine form. In the crystal, molecules are linked by N—H...O and N—H...N hydrogen bonds into a two-dimensional network parallel to the ab plane.
rac-(2R*,3S*,5S*,6R*,7S*,8S*)-7,8-Dichlorobicyclo[2.2.2]octane-2,3,5,6-tetrayl tetraacetate
Ertan Şahin,Arif Baran,Metin Balcı
Acta Crystallographica Section E , 2009, DOI: 10.1107/s160053680900484x
Abstract: The title compound, C16H20Cl2O8, contains a central bicyclo[2.2.2]octane skeleton with slightly twisted conformation. In this structure, the C—C bond lengths are in the range 1.525 (2)–1.552 (2) . Two sides of this skeleton have cis,cis acetoxy substituents and the Cl atoms have a trans arrangement. An extensive network of weak C—H...O interactions stabilizes the crystal structure.
1,4-Diazoniabicyclo[2.2.2]octane terephthalate
E Yang,Xu-Chun Song,Jian-Wei Zhu
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808025312
Abstract: In the title compound, C6H14N2+·C8H4O42 , the protonated 1,4-diazoniabicyclo[2.2.2]octane cations and the deprotonated terephthalate anions are alternately linked by N—H...O hydrogen bonds into chains.
Synthesis and Study of Anti Parkinsonism activity of 8-azabicyclo [3.2.1] octane Analogs  [PDF]
Saurav M. Verma
Pharmacology & Pharmacy (PP) , 2011, DOI: 10.4236/pp.2011.22012
Abstract: Parkinson's disease (PD) is a common neurodegenerative condition associated with the degeneration of dopaminergic neurons in the zona compacta of the substantia nigra. 3D QSAR study of 8-azabicyclo [3.2.1] octane analogs which serves as the pathfinder for the design of novel molecule for anti Parkinsonism. Five compounds of 8-azabicyclo [3.2.1] octane analogs are synthesized and the anti Parkinsonism activity and brain dopamine level were studied on albino mice. The anti Parkinsonian activity was determined by the effect of test compound A-F on drug induced catatonia using the method of Morpurgo. Atropine as well as compounds B and E significantly reduced the catatonic responses and tremors induced by chlorpromazine. The level of dopamine was measured after the administration of atropine and the test compounds in brain of mice. The study reveals that the compounds B and E have exhibited significant activity over atropine.
1-Bromomethyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide  [cached]
Aaron D. Finke,Danielle L. Gray,Jeffrey S. Moore
Acta Crystallographica Section E , 2010, DOI: 10.1107/s1600536810000292
Abstract: The title compound, C7H14BrN2+·Br , was prepared by nucleophilic substitution of DABCO (systematic name: 1,4-diazabicyclo[2.2.2]octane) with dibromomethane in acetone. The structure features Br...H close contacts (2.79 and 2.90 ) as well as a weak bromine–bromide interaction [3.6625 (6) ].
1-Cyanomethyl-1,4-diazoniabicyclo[2.2.2]octane tetrachloridomanganate(II)  [cached]
Min Guo,Min Min Zhao
Acta Crystallographica Section E , 2010, DOI: 10.1107/s160053681004047x
Abstract: In the crystal structure of the title compound, (C8H15N3)[MnCl4], the Mn atom is coordinated by four chloride ligands in a slightly distorted tetrahedral geometry. Each [MnCl4]2 anion is connected to the 1-cyanomethyl-1,4-diazoniabicyclo[2.2.2]octane dications by N—H...Cl hydrogen bonds, forming chains parallel to [001].
1-Cyanomethyl-1,4-diazoniabicyclo[2.2.2]octane tetrachloridocadmate(II)  [cached]
Yi Zhang,Bo Han Zhu
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812017801
Abstract: In the title salt, (C8H15N3)[CdCl4], four Cl atoms coordinate the CdII atom in a slightly distorted tetrahedral geometry. In the crystal, each [CdCl4]2 anion is connected to the 1-cyanomethyl-1,4-diazoniabicyclo[2.2.2]octane dications by N—H...Cl hydrogen bonds, forming chains parallel to [001]. C—H...Cl interactions also occur.
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