| 1. |
- Batta, Gy., et al.
(författare)
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C‐19 configurational assignments in some morphine derivatives by homonuclear NOE
- 1992
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Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 30:13, s. S96-S104
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Tidskriftsartikel (refereegranskat)abstract
- Azidolysis‐thermolysis of C‐19 diastereomer tosyl esters of morphine derivatives resulted in the formation of a new substituted 4‐azatetracyclo [4.4.02,4.03,8] decane ring system. As the course of such transformations depends on the chirality of C‐19, its relative configuration was determined both in the starting materials and in the new compounds. To this end a semiquantitative 1H{1H} NOE interpretation was combined with MMX molecular mechanics. Interestingly, both in the starting materials with a rotating C‐7—C‐19 bond and in the fairly rigid aziridine ring‐containing products, the same (H‐8α{19‐Me}) NOE effects were the most informative on the stereochemistry. In addition full a priori 1H and 13C assignments of 13 compounds are presented.
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| 2. |
- Engdahl, Carin, et al.
(författare)
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Long‑Range Deuterium Isotope Effects on 13C NMR Shifts of Intramolecularly Hydrogen‑Bonded 9‑Hydroxyphenalen‑1‑ones
- 1991
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Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 29:1, s. 54-62
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Tidskriftsartikel (refereegranskat)abstract
- The 1H and 13C NMR spectra of 9-hydroxyphenalenone (1) and 9-hydroxy-2-methylphenalenone (2) have been completely assigned. Primary and secondary deuterium isotope effects were determined in three solvents (chloroform, acetone and dimethyl sulphoxide), including the effect of temperature on the secondary isotope effects. Both negative and large long-range secondary isotope effects were found for both 1 and 2. The average secondary isotope effects for corresponding carbons follow the same sign and magnitude pattern in both compounds.
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| 3. |
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| 4. |
- Gogoll, Adolf, et al.
(författare)
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Structural Assignment of σ-π-Palladium Complexes by 2D NMR
- 1993
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Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 31:10, s. 954-959
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Tidskriftsartikel (refereegranskat)abstract
- A series of (σ-π)palladium complexes derived from cyclooctadiene were investigated by 1H, 13C and 19F NMR. The stereochemical assignment was based on intramolecular NOEs in conjunction with molecular modelling and semi-empirical methods, and confirmed by interligand NOEs in nitrogen chelate complexes derived from the title compounds. The nitrogen chelating ligands are involved in a rotation with respect to the ligand-palladium axis.
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| 5. |
- Szabo, Zoltan, Associate professor, et al.
(författare)
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1H and 13C NMR study of novel fused 1,2,4‐triazole heterocycles
- 1992
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Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 30:11, s. 1111-1116
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Tidskriftsartikel (refereegranskat)abstract
- The 1H and 13C NMR spectra of some novel 1,2,4‐triazolo [1,3] thiazinoquinoline isomeric pairs are interpreted in terms of structural assignments. The structure of most compounds has been confirmed by NOE difference spectroscopy. Characteristic differences have been observed in both 1H and 13C NMR spectra of these isomeric Pairs: some of the 1H and 13C chemical shifts, and also the one bond 13C1H couplings of triazole protons, differ consistently in the NMR spectra of the isomers. The coupling constants have been determined using a combination of INEPT and chemical shift selective filtering.
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| 6. |
- Szabó, Zoltan, Associate professor, et al.
(författare)
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Interpretation of the 13C NMR spectra of 3‐benzylideneflavanones, 3‐benzylflavone and 3‐benzyl‐1‐thioflavone derivatives
- 1993
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Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 31:4, s. 418-421
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Tidskriftsartikel (refereegranskat)abstract
- 13C NMR spectra of 3‐benzylflavones, 3‐benzylideneflavanones, 3‐benzyl‐4‐thioflavones, 3‐benzyl‐1‐thioflavones, 3‐benzyl‐1,4‐dithioflavones and 3‐benzyl‐1‐thioflavone‐1,1‐dioxides were analysed and correlated to evaluate the consequences of the replacement of oxygen with sulphur.
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