| | 1 | Author
| Jörg Fleischhauer3, Sven Gabriel3, A.Ndreas Job3, D. Ieter Enders3, Axel Wollmerb | Requires cookie* | | | Title
| CD-Spectroscopic Investigations for the Determination of the Absolute Configuration of (4/?,6S,7S)-Serricomin  | | | | Abstract
| The absolute configuration of the conformationally flexible (4i?,6S,7S)-serricornin, a non natural isomer of the female-produced sex pheromone of the cigarette beetle (Lasioderma serricorne), was determined by comparison of measured and calculated circular dichroism spectra. The rotational strengths were calculated by means of the semiempirical CNDO/2S-method. The total synthesis was accomplished by the SAMP/RAMP-hydrazone method. | | | |
Reference
| Z. Naturforsch. 56b, 1344—1348 (2001); received July 26 2001 | | | |
Published
| 2001 | | | |
Keywords
| Serricornin, CD Spectra, Absolute Configuration | | | |
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| default:Reihe_B/56/ZNB-2001-56b-1344.pdf | | | | Identifier
| ZNB-2001-56b-1344 | | | | Volume
| 56 | |
| 2 | Author
| KhalidM. Ohammed Khana, Farnaz Malikb, Mashooda Hasanb, Shahnaz Perveen3, Jodwiga Frelekc, G. Ünther Snatzke+, Wolfgang Voelter3 | Requires cookie* | | | Title
| Circular Dichroism Studies on New Optically Active 1,5-Benzodiazepine Derivatives | | | | Abstract
| From thirty three new optically active 1,5-benzodiazepine derivatives the UV and CD data are reported and the bands discussed related to corresponding electronic transitions respectively stereochemical features. | | | |
Reference
| Z. Naturforsch. 51b, 588—598 (1996); recieved September 26 1995 | | | |
Published
| 1996 | | | |
Keywords
| CD Spectra, Benzodiazepines, Chiral 1, 5-Benzodiazepine Derivatives | | | |
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| default:Reihe_B/51/ZNB-1996-51b-0588.pdf | | | | Identifier
| ZNB-1996-51b-0588 | | | | Volume
| 51 | |
| 3 | Author
| Jörg Fleischhauer3, Sven Gabriel3, Dieter Enders3, Anja Nühring3, Axel Wollmerb | Requires cookie* | | | Title
| CD-Spectroscopic Investigations for the Determination of the Absolute Configuration of a-Alkylated 1,4-CycIohexanedione Derivatives | | | | Abstract
| The absolute configuration of the conformationally flexible six membered ring system 2-me-thyl-and 2,6-dimethyl-l,4-cyclohexanedione monoethylene acetal was determined by compar ison of measured and calculated CD spectra. The rotational strengths were calculated by means of the CNDO/S-method assuming R at the stereogenic center. The results were compared with the predictions made by the octant rule. The enantiomerically pure material was synthesized via the corresponding SAMP-and RAMP-hydrazones. | | | |
Reference
| Z. Naturforsch. 55b, 1011—1014 (2000); received July 3 2000 | | | |
Published
| 2000 | | | |
Keywords
| 1, 4-Cyclohexanedione Derivatives, Absolute Configuration, CD Spectra | | | |
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| default:Reihe_B/55/ZNB-2000-55b-1011.pdf | | | | Identifier
| ZNB-2000-55b-1011 | | | | Volume
| 55 | |
| 4 | Author
| Henri Brunner, Jean-Claude Leblanc | Requires cookie* | | | Title
| (CH2OCH3)P(C6H5)2N(CH3)R * mit chiralen Fe-Atomen Optically Active Transition Metal Complexes, LXX [1] Preparation of the Optically Active Diastereoisomers CsHsFe^O)- (CH2OCH3)P(C6H5)2N(CH3)R* with Chiral Fe Atoms | | | | Abstract
| The two diastereoisomers CsHsFe(CO)(CH2OCH3)P(CeHs)2N(CH3)R* (Ba, b), with R* = 0S)-CH(CH3)(C6H5), differing only in the Fe configuration, have been obtained by photochemical reaction of C5H5Fe(C0)2CH20CH3 with (£)-(+)-P(C6H5)2N(CH3)R*. The optically pure isomer 3 a can be isolated by chromatography at low temperature; its chiroptical properties are discussed. | | | |
Reference
| Z. Naturforsch. 35b, 1491—1493 (1980); eingegangen am 8. August 1980 | | | |
Published
| 1980 | | | |
Keywords
| Diastereoisomers, Fe-Configuration, Separation, CD Spectra | | | |
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| default:Reihe_B/35/ZNB-1980-35b-1491_n.pdf | | | | Identifier
| ZNB-1980-35b-1491_n | | | | Volume
| 35 | |
| 6 | Author
| Kaeko Kikuchi, Yoshio Taniyama, Ryuji Marumoto | Requires cookie* | | | Title
| Evaluation of the 2 NH 2 A—T Pair in Hybridization, I Synthesis of the DNA/RNA Hybrid Oligomers Containing 2-Aminoadenosines | | | | Abstract
| DNA decamers containing 2-aminoadenosine were synthesized. Oligonucleotide duplexes in-cluding the 2 NH2A—T base pairs were prepared and their Tm profile examined. Contrary to expectation, elevation of the Tm value by the 2 NH2 group is very small in DNA/RNA duplexes. From the CD spectra measurement, we assume that the distortion of the B-DNA structure caused by scattered DNA/RNA base pairing diminishes the efficient hydrogen bonding and base stacking of the duplexes. It was also found that the DNA duplexes containing 2-aminoadenosine hybrids are considerably resistant to ribonuclease T2 or nuclease PI digestion. | | | |
Reference
| Z. Naturforsch. 43b, 623—630 (1988); received October 12 1987/February 1 1988 | | | |
Published
| 1988 | | | |
Keywords
| DNA Probe, Hybridization, 2-Aminoadenosine, CD Spectra, DNA/RNA Hybrid Oligomer | | | |
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| default:Reihe_B/43/ZNB-1988-43b-0623.pdf | | | | Identifier
| ZNB-1988-43b-0623 | | | | Volume
| 43 | |
| 7 | Author
| Zofia Plesnar3, Stanisław Malanowski3, Zenon Lotowskib, JacekW. Morzyckib, Jadwiga Frelek, Jacek Wójcikd | Requires cookie* | | | Title
| Stereospecific Association of C-20 Epimers of 3/?-Hydroxy-16-oxo-24-nor-17-azachol-5-eno-23-nitryle | | | | Abstract
| The cryoscopic measurements show that title compounds are strongly associated in CHC13 solutions. The association of the 20 R epimer is distinctly less pronounced than that of the 205 epipmer. Self-association of the 205 epimer leads to the formation of very large com plexes. The 20 R epimer forms associates via water molecules. The dissimilarity may be ex plained in terms of different accessibility of the lactam carbonyl groups in the two epimers for the association. It is proposed that the association process is controlled by the configura tion at the carbon atom C(20) and conformation around the C(20)-C(22) bond. Populations of side chain conformations of both epimers were determined by means of proton nuclear magnetic resonance. It was found for the 20 R epimer that the t and the -g rotamers are almost equally populated, and the rotamer +g is excluded. For the 205 epimer the +g rotamer predominates over the t one, and the -g rotamer is excluded. The N M R data are fully consistent with the results of the molecular modelling studies. | | | |
Reference
| Z. Naturforsch. 52b, 749—756 (1997); received | | | |
Published
| 1997 | | | |
Keywords
| Self-Association, Cryoscopic Measurements, Conformational Analysis, CD Spectra, Azasteroids | | | |
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| default:Reihe_B/52/ZNB-1997-52b-0749.pdf | | | | Identifier
| ZNB-1997-52b-0749 | | | | Volume
| 52 | |
| 8 | Author
| Thomas Buhse, Wolfram Thiemann | Requires cookie* | | | Title
| Chiral Intermediates and the Oscillatory Effect of Circular Dichroism in the Belousov -Zhabotinskii Type Reaction of L-Ascorbic Acid | | | | Abstract
| Investigating the Belousov-Z habotinskii (BZ) type reaction of an acidic L-ascorbic acid (AA) / potassium brom ate / cerous sulfate system, an oscillatory effect of circular dichroism is detectable at A = 300 nm. HPLC analysis o f the oscillatory mixture and spectroscopic experi ments indicate that this effect is caused by 3,4,5-trihydroxy-2-oxo-L-valeraldehyde (TVA) -a C5 oxidation fragment of AA. Because of the bromide ion production occurring before the metal catalyst addition the AA system shows no preoscillatory phase and a rather short entire length of oscillation up to a maximum of 20 min. Since AA is not brom inated but oxidized by bromine which is formed by the Landolt typ "clock reaction" o f AA with acidic brom ate, par tially bromine-hydrolysis-controlled (BHC) oscillations are discussed for the overall mecha nism of this BZ system. | | | |
Reference
| Z. Naturforsch. 46b, 1406—1414 (1991); received | | | |
Published
| 1991 | | | |
Keywords
| M arch 1, 1991 Chemical Oscillations, CD Spectra, L-Ascorbic Acid, B elousov-Z habotinskii Reaction, Bromate | | | |
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| default:Reihe_B/46/ZNB-1991-46b-1406.pdf | | | | Identifier
| ZNB-1991-46b-1406 | | | | Volume
| 46 | |
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