Determination of the absolute configuration and optical purity of [(η5-C5H5)Fe(CO)(PPh3)COMe]; X-ray crystal structure of (R)-{(η5-C5H5)Fe(CO)(PPh3)COCH2CH2O[(R)-menthyl]}

Author(s):  
Stephen G. Davies ◽  
Isabelle M. Dordor-Hedgecock ◽  
Kevin H. Sutton ◽  
Jonathan C. Walker ◽  
Christopher Bourne ◽  
...  
1999 ◽  
Vol 23 (9) ◽  
pp. 578-579
Author(s):  
Rainer Schobert ◽  
Hermann Pfab ◽  
Jutta Böhmer ◽  
Frank Hampel ◽  
Andreas Werner

Racemates of (η3-allyl)tricarbonyliron lactone complex Fe(CO)3{η1:η3-C(O)XCH2CHCMeCH2} 1a (X = O) and (η3-allyl)tricarbonyliron lactam complex 2a (X = NMe) are resolved on a preparative scale by HPLC on cellulose tris(3,5-dimethylphenyl)carbamate/silica gel RP-8 and the absolute configuration of (-)-2a is determined by X-ray crystal structure analysis.


1987 ◽  
Vol 65 (6) ◽  
pp. 1308-1312 ◽  
Author(s):  
André Michel ◽  
Guy Evrard ◽  
B. Norberg

The synthesis of the title compounds has been described recently. It was anticipated that the product would be a diastereomeric mixture. Surprisingly, only one isomer was obtained. The present work is an attempt to find the conformationnal properties accounting for those observations. X-ray structure determination of 3R-[p-hydroxybenzyl]-6-carbethoxy-2-oxopiperazine shows that the molecule adopts a folded conformation and that the absolute configuration at C6 is [R]. Investigation in solution using 1H nuclear magnetic resonance shows the existence of three conformers and discusses the relative populations. Those findings are also relevant in terms of the activity of such compounds at the opiate receptor level.


2013 ◽  
Vol 69 (11) ◽  
pp. 1411-1413 ◽  
Author(s):  
Yuko Kawanami ◽  
Hidekazu Tanaka ◽  
Jun-ichi Mizoguchi ◽  
Nobuko Kanehisa ◽  
Gaku Fukuhara ◽  
...  

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.


1998 ◽  
Vol 63 (3) ◽  
pp. 425-433 ◽  
Author(s):  
Michal Hušák ◽  
Bohumil Kratochvíl ◽  
Petr Sedmera ◽  
Vladimír Havlíček ◽  
Hana Votavová ◽  
...  

Four isomers of terguride, a semisynthetic ergot alkaloid derivative, have been prepared by catalytic hydrogenation of (5R,8S)- and (5S,8S)-lisuride [1,1-diethyl-3-(6-methyl-8-ergolenyl)urea]. Relative stereochemistry of the isomers is based on NMR and CD spectra. Absolute configuration of all the series has been confirmed by the X-ray crystal structure determination of (5R,8S,10S)-terguride 2-bromobenzoate [1,1-diethyl-3-(6-methyl-8-isoergolenyl)urea, cis-dihydrolisuride].


2005 ◽  
Vol 117 (15) ◽  
pp. 2302-2305 ◽  
Author(s):  
Shunsuke Kuwahara ◽  
Kazuhiro Obata ◽  
Kazuhiro Yoshida ◽  
Takatoshi Matsumoto ◽  
Nobuyuki Harada ◽  
...  

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