The Resolution and Absolute Configuration of 2,3-Methanopyroglutamic Acid, 3-Oxo-2-azabicyclo[3,1,0]hexane-1-carboxylic Acid

1992 ◽  
Vol 65 (10) ◽  
pp. 2668-2671 ◽  
Author(s):  
Hiroaki Kodama ◽  
Shinichi Matsui ◽  
Michio Kondo ◽  
Charles H. Stammer
Keyword(s):  
Carboxylic Acid ◽  
Absolute Configuration

Absolute configuration determination of theanti-head-to-head photocyclodimer of anthracene-2-carboxylic acid through cocrystallization withL-prolinol

2013 ◽  
Vol 69 (11) ◽  
pp. 1411-1413 ◽  
Author(s):  
Yuko Kawanami ◽  
Hidekazu Tanaka ◽  
Jun-ichi Mizoguchi ◽  
Nobuko Kanehisa ◽  
Gaku Fukuhara ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Circular Dichroism ◽  
Carboxylic Acid ◽  
Absolute Configuration ◽  
Void Space ◽  
Circular Dichroism Spectra ◽  
The Absolute ◽  
Circular Dichroïsm ◽  
Hydrogen Bonded

The absolute configuration has been established of the enantiopureanti-head-to-head cyclodimer of anthracene-2-carboxylic acid (AC) cocrystallized with L-propinol and dichloromethane [systematic name: (S)-2-(hydroxymethyl)pyrrolidin-1-ium (5R,6S,11R,12S)-8-carboxy-5,6,11,12-tetrahydro-5,12:6,11-bis([1,2]benzeno)dibenzo[a,e][8]annulene-2-carboxylate dichloromethane monosolvate], C5H12NO+·C30H19O4−·CH2Cl2. In the crystal structure, the AC dimer interacts with L-prolinol through a nine-membered hydrogen-bonded ring [R22(9)], while the dichloromethane molecule is incorporated to fill the void space. The absolute configuration determined in this study verifies a recent assignment made by comparing theoreticalversusexperimental circular dichroism spectra.

scholarly journals Enantiomeric Resolution and Absolute Configuration of a Chiral δ-Lactam, Useful Intermediate for the Synthesis of Bioactive Compounds

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 6023
Author(s):  
Roberta Listro ◽  
Giacomo Rossino ◽  
Serena Della Volpe ◽  
Rita Stabile ◽  
Massimo Boiocchi ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Bioactive Compounds ◽  
Absolute Configuration ◽  
Chiral Center ◽  
Reference Compound ◽  
Enantiomeric Resolution ◽  
Enantiomerically Pure ◽  
X Ray ◽  
The Past ◽  
Configuration Assignment

During the past several years, the frequency of discovery of new molecular entities based on γ- or δ-lactam scaffolds has increased continuously. Most of them are characterized by the presence of at least one chiral center. Herein, we present the preparation, isolation and the absolute configuration assignment of enantiomeric 2-(4-bromophenyl)-1-isobutyl-6-oxopiperidin-3-carboxylic acid (trans-1). For the preparation of racemic trans-1, the Castagnoli-Cushman reaction was employed. (Semi)-preparative enantioselective HPLC allowed to obtain enantiomerically pure trans-1 whose absolute configuration was assigned by X-ray diffractometry. Compound (+)-(2R,3R)-1 represents a reference compound for the configurational study of structurally related lactams.

Cobalt(III) Complexes of a Stereospecific Ligand Derived from (S)-Proline

1979 ◽  
Vol 32 (8) ◽  
pp. 1661 ◽  
Author(s):  
T Woon ◽  
MJ O'Conner
Keyword(s):  
Aqueous Solution ◽  
Carboxylic Acid ◽  
Absolute Configuration ◽  
Cotton Effect ◽  
Low Energy ◽  
Spectral Measurements ◽  
Asymmetric Carbon Atom ◽  
Geometrical Isomers ◽  
Negative Cotton Effect ◽  
Asymmetric Carbon

The quadridentate ligand, (2S,2'S)-1,1'-(ethane-1,2-diyl)bis(pyrrolidine-2-carboxylic acid) dihydrochloride (H2pren,2HCl), has been derived from (S)-proline. The preparations of the cobalt(III) complexes Na [Co(pren)(CO3)],3H2O, [CO(pren)(H2O)2] ClO4,- 2H2O and [Co(pren)(H2O)Cl],1�5H2O are described. All exist as cis-α geometrical isomers. 13C N.M.R. and absorption spectral measurements confirm the cis-α arrangement. The complex cis-α- [Co(pren)(H2O)Cl],1�5H2O rapidly aquates with retention of configuration. The compounds having actual or near C2 symmetry exhibit a strong negative c.d. band under the 1A1g → 1T1g cubic absorption band which is due to the 1A1 →1E tetragonal component, consistent with the Δ absolute configuration imposed by the (S) configuration of the asymmetric carbon atom in the (S)-proline moiety. The o.r.d. spectrum of cis-α-Na [Co(pren)CO3],3H2O in aqueous solution has a negative Cotton effect at low energy as expected for the Δ absolute configuration.

The Chemistry of Eremophila spp. XI. The Absolute Configuration of Dihydroxyserrulatic Acid

1979 ◽  
Vol 32 (9) ◽  
pp. 2079 ◽  
Author(s):  
KD Croft ◽  
EL Ghisalberti ◽  
PR Jefferies ◽  
AD Stuart
Keyword(s):  
Carboxylic Acid ◽  
Absolute Configuration ◽  
The Absolute

Dihydroxyserrulatic acid (1), a diterpene from Eremophila serrulata, has been degraded to the naphthalene (2) which was shown to have the R-configuration. The diterpene acid can now be designated as (5R,8S,1'S)-4-hydroxy-8-(6'-hydroxy-1',5'-dimethylhex-4-enyl)-5-methyl-5,6,7,8-tetrahydronaphthalene-2-carboxylic acid.

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